This page explains BigQuery expressions, including functions and operators.
Function call rules
The following rules apply to all functions unless explicitly indicated otherwise in the function description:
- For functions that accept numeric types, if one operand is a floating point operand and the other operand is another numeric type, both operands are converted to FLOAT64 before the function is evaluated.
-
If an operand is
NULL, the result isNULL, with the exception of the IS operator. -
For functions that are time zone sensitive (as indicated in the function description), the default time zone, UTC, is used if a time zone is not specified.
SAFE. prefix
Syntax:
SAFE.function_name()Description
If you begin a function with the SAFE. prefix, it will return NULL instead
of an error. The SAFE. prefix only prevents errors from the prefixed function
itself: it does not prevent errors that occur while evaluating argument
expressions. The SAFE. prefix only prevents errors that occur because of the
value of the function inputs, such as "value out of range" errors; other
errors, such as internal or system errors, may still occur. If the function
does not return an error, SAFE. has no effect on the output. If the function
never returns an error, like RAND, then SAFE. has no effect.
Operators, such as + and =, do not support the SAFE.
prefix. To prevent errors from a division
operation, use SAFE_DIVIDE. Some operators,
such as IN, ARRAY, and UNNEST, resemble functions, but do not support the
SAFE. prefix. The CAST and EXTRACT functions also do not support the
SAFE. prefix. To prevent errors from casting, use
SAFE_CAST.
Example
In the following example, the first use of the SUBSTR function would normally
return an error, because the function does not support length arguments with
negative values. However, the SAFE. prefix causes the function to return
NULL instead. The second use of the SUBSTR function provides the expected
output: the SAFE. prefix has no effect.
SELECT SAFE.SUBSTR('foo', 0, -2) AS safe_output UNION ALL
SELECT SAFE.SUBSTR('bar', 0, 2) AS safe_output;
+-------------+
| safe_output |
+-------------+
| NULL |
| ba |
+-------------+Supported functions
BigQuery supports the use of the SAFE. prefix with most scalar
functions that can raise errors, including STRING functions,
math functions, DATE functions,
DATETIME functions, and
TIMESTAMP functions. BigQuery does not support
the use of the SAFE. prefix with aggregate,
analytic, or user-defined functions.
Conversion rules
"Conversion" includes, but is not limited to, casting and coercion.
- Casting is explicit conversion and uses the
CAST()function. - Coercion is implicit conversion, which BigQuery performs automatically under the conditions described below.
- There is a third group of conversion
functions that have their own function
names, such as
UNIX_DATE().
The table below summarizes all possible CAST and coercion possibilities for
BigQuery data types. "Coercion To" applies to all expressions of a
given data type (e.g. a column)
, but literals
and parameters can also be coerced. See Literal Coercion and
Parameter Coercion for details.
| From Type | CAST to | Coercion To |
|---|---|---|
| INT64 | BOOL INT64 NUMERIC FLOAT64 STRING |
FLOAT64 NUMERIC |
| NUMERIC | INT64 NUMERIC FLOAT64 STRING |
FLOAT64 |
| FLOAT64 | INT64 NUMERIC FLOAT64 STRING |
|
| BOOL | BOOL INT64 STRING |
|
| STRING | BOOL INT64 NUMERIC FLOAT64 STRING BYTES DATE DATETIME TIME TIMESTAMP |
|
| BYTES | BYTES STRING |
|
| DATE | DATE DATETIME STRING TIMESTAMP |
|
| DATETIME | DATE DATETIME STRING TIME TIMESTAMP |
|
| TIME | STRING TIME |
|
| TIMESTAMP | DATE DATETIME STRING TIME TIMESTAMP |
|
| ARRAY | ARRAY | |
| STRUCT | STRUCT |
Casting
Syntax:
CAST(expr AS typename)Cast syntax is used in a query to indicate that the result type of an expression should be converted to some other type.
Example:
CAST(x=1 AS STRING)This results in "true" if x is 1, "false" for any other non-NULL
value, and NULL if x is NULL.
Casts between supported types that do not successfully map from the original value to the target domain produce runtime errors. For example, casting BYTES to STRING where the byte sequence is not valid UTF-8 results in a runtime error.
When casting an expression x of the following types, these rules apply:
| From | To | Rule(s) when casting x |
|---|---|---|
| INT64 | FLOAT64 | Returns a close but potentially not exact FLOAT64 value. |
| INT64 | BOOL | Returns FALSE if x is 0, TRUE otherwise. |
| NUMERIC | Floating Point | NUMERIC will convert to the closest floating point number with a possible loss of precision. |
| FLOAT64 | INT64 | Returns the closest INT64 value. Halfway cases such as 1.5 or -0.5 round away from zero. |
| FLOAT64 | STRING | Returns an approximate string representation. |
| FLOAT64 | NUMERIC | If the floating point number has more than nine digits after the decimal
point, it will round
half away from zero. Casting a NaN, +inf or
-inf will return an error. Casting a value
outside the range of NUMERIC will
return an overflow error.
|
| BOOL | INT64 | Returns 1 if x is TRUE, 0 otherwise. |
| BOOL | STRING | Returns "true" if x is TRUE, "false" otherwise. |
| STRING | FLOAT64 | Returns x as a
FLOAT64
value, interpreting it as having the same form as a valid
FLOAT64
literal.Also supports casts from "inf", "+inf", "-inf", and "nan".Conversions are case-insensitive. |
| STRING | NUMERIC | The numeric literal contained in the STRING must not exceed the
maximum precision or range of the
NUMERIC type, or an error will occur. If the number of digits
after the decimal point exceeds nine, then the resulting NUMERIC
value will round
half
away from zero to have nine digits after the decimal point.
|
| STRING | BOOL | Returns TRUE if x is "true" and
FALSE if x is "false"All other values of x are invalid and throw an error instead of
casting to BOOL.STRINGs are case-insensitive when converting to BOOL. |
| STRING | BYTES | STRINGs are cast to BYTES using UTF-8 encoding. For example, the STRING "©", when cast to BYTES, would become a 2-byte sequence with the hex values C2 and A9. |
| BYTES | STRING | Returns x interpreted as a UTF-8 STRING.For example, the BYTES literal b'\xc2\xa9', when cast to STRING, is interpreted as UTF-8 and
becomes the unicode character "©".An error occurs if x is not valid UTF-8. |
| ARRAY | ARRAY | Must be the exact same ARRAY type. |
| STRUCT | STRUCT | Allowed if the following conditions are met:
|
Safe casting
When using CAST, a query can fail if BigQuery is unable to perform
the cast. For example, the following query generates an error:
SELECT CAST("apple" AS INT64) AS not_a_number;If you want to protect your queries from these types of errors, you can use
SAFE_CAST. SAFE_CAST is identical to CAST, except it returns NULL instead
of raising an error.
SELECT SAFE_CAST("apple" AS INT64) AS not_a_number;
+--------------+
| not_a_number |
+--------------+
| NULL |
+--------------+If you are casting from bytes to strings, you can also use the
function, SAFE_CONVERT_BYTES_TO_STRING. Any invalid UTF-8 characters are
replaced with the unicode replacement character, U+FFFD. See
SAFE_CONVERT_BYTES_TO_STRING for more
information.
Casting hex strings to integers
If you are working with hex strings (0x123), you can cast those strings as
integers:
SELECT '0x123' as hex_value, CAST('0x123' as INT64) as hex_to_int;
+-----------+------------+
| hex_value | hex_to_int |
+-----------+------------+
| 0x123 | 291 |
+-----------+------------+
SELECT '0x123' as hex_value, CAST('-0x123' as INT64) as hex_to_int;
+-----------+------------+
| hex_value | hex_to_int |
+-----------+------------+
| 0x123 | -291 |
+-----------+------------+Casting date types
BigQuery supports casting date types to/from strings as follows:
CAST(date_expression AS STRING)
CAST(string_expression AS DATE)Casting from a date type to a string is independent of time zone and is of the
form YYYY-MM-DD. When casting from string to date, the string must conform to
the supported date literal format, and is independent of time zone. If the string
expression is invalid or represents a date that is outside of the supported
min/max range, then an error is produced.
Casting timestamp types
BigQuery supports casting timestamp types to/from strings as follows:
CAST(timestamp_expression AS STRING)
CAST(string_expression AS TIMESTAMP)When casting from timestamp types to string, the timestamp is interpreted using the default time zone, UTC. The number of subsecond digits produced depends on the number of trailing zeroes in the subsecond part: the CAST function will truncate zero, three, or six digits.
When casting from string to a timestamp, string_expression must conform to
the supported timestamp literal formats, or else a runtime error
occurs. The string_expression may itself contain a time_zone—see
time zones.
If there is a time zone in the string_expression, that time zone is used for
conversion, otherwise the default time zone, UTC, is used.
If the string has fewer than six digits, then it is implicitly widened.
An error is produced if the string_expression is invalid, has more than six
subsecond digits (i.e. precision greater than microseconds), or represents a
time outside of the supported timestamp range.
Casting between date and timestamp types
BigQuery supports casting between date and timestamp types as follows:
CAST(date_expression AS TIMESTAMP)
CAST(timestamp_expression AS DATE)Casting from a date to a timestamp interprets date_expression as of midnight
(start of the day) in the default time zone, UTC. Casting
from a timestamp to date effectively truncates the timestamp as of the default
time zone.
Coercion
BigQuery coerces the result type of an expression to another type if needed to match function signatures. For example, if function func() is defined to take a single argument of type INT64 and an expression is used as an argument that has a result type of FLOAT64, then the result of the expression will be coerced to INT64 type before func() is computed.
Literal coercion
BigQuery supports the following literal coercions:
| Input Data Type | Result Data Type | Notes |
|---|---|---|
| STRING literal | DATE TIMESTAMP |
Literal coercion is needed when the actual literal type is different from the
type expected by the function in question. For
example, if function func() takes a DATE argument, then the expression
func("2014-09-27") is valid because the STRING literal "2014-09-27"
is coerced to DATE.
Literal conversion is evaluated at analysis time, and gives an error if the input literal cannot be converted successfully to the target type.
Note: String literals do not coerce to numeric types.
Parameter coercion
BigQuery supports the following parameter coercions:
| Input Data Type | Result Data Type |
|---|---|
| STRING parameter |
If the parameter value cannot be coerced successfully to the target type, an error is provided.
Additional conversion functions
BigQuery provides the following additional conversion functions:
Aggregate functions
An aggregate function is a function that performs a calculation on a set of values. COUNT, MIN and MAX are examples of aggregate functions.
SELECT COUNT(*) as total_count, COUNT(fruit) as non_null_count,
MIN(fruit) as min, MAX(fruit) as max
FROM UNNEST([NULL, "apple", "pear", "orange"]) as fruit;+-------------+----------------+-------+------+
| total_count | non_null_count | min | max |
+-------------+----------------+-------+------+
| 4 | 3 | apple | pear |
+-------------+----------------+-------+------+The following sections describe the aggregate functions that BigQuery supports.
ANY_VALUE
ANY_VALUE(expression) [OVER (...)]Description
Returns any value from the input or NULL if there are zero input rows.
The value
returned is non-deterministic, which means you might receive a different result
each time you use this function.
Supported Argument Types
Any
Optional Clause
OVER: Specifies a window. See
Analytic Functions.
Returned Data Types
Matches the input data type.
Examples
SELECT ANY_VALUE(fruit) as any_value
FROM UNNEST(["apple", "banana", "pear"]) as fruit;
+-----------+
| any_value |
+-----------+
| apple |
+-----------+
SELECT
fruit,
ANY_VALUE(fruit) OVER (ORDER BY LENGTH(fruit) ROWS BETWEEN 1 PRECEDING AND CURRENT ROW) AS any_value
FROM UNNEST(["apple", "banana", "pear"]) as fruit;
+--------+-----------+
| fruit | any_value |
+--------+-----------+
| pear | pear |
| apple | pear |
| banana | apple |
+--------+-----------+ARRAY_AGG
ARRAY_AGG([DISTINCT] expression [{IGNORE|RESPECT} NULLS]
[ORDER BY key [{ASC|DESC}] [, ... ]] [LIMIT n])
[OVER (...)]Description
Returns an ARRAY of expression values.
Supported Argument Types
All data types except ARRAY.
Optional Clauses
The clauses are applied in the following order:
-
OVER: Specifies a window. See Analytic Functions. This clause is currently incompatible with all other clauses withinARRAY_AGG(). -
DISTINCT: Each distinct value ofexpressionis aggregated only once into the result. -
IGNORE NULLSorRESPECT NULLS: IfIGNORE NULLSis specified, the NULL values are excluded from the result. IfRESPECT NULLSis specified or if neither is specified, the NULL values are included in the result (an error is raised, however, if an array in the final query result contains a NULL element). -
ORDER BY: Specifies the order of the values.- For each sort key, the default sort direction is
ASC. - NULLs: In the context of the
ORDER BYclause, NULLs are the minimum possible value; that is, NULLs appear first inASCsorts and last inDESCsorts. - Floating point data types: see Floating Point Semantics on ordering and grouping.
- If
DISTINCTis also specified, then the sort key must be the same asexpression. - If
ORDER BYis not specified, the order of the elements in the output array is non-deterministic, which means you might receive a different result each time you use this function.
- For each sort key, the default sort direction is
-
LIMIT: Specifies the maximum number ofexpressioninputs in the result. The limitnmust be a constant INT64.
Returned Data Types
ARRAY
If there are zero input rows, this function returns NULL.
Examples
SELECT FORMAT("%T", ARRAY_AGG(x)) AS array_agg
FROM UNNEST([2, 1, -2, 3, -2, 1, 2]) AS x;
+-------------------------+
| array_agg |
+-------------------------+
| [2, 1, -2, 3, -2, 1, 2] |
+-------------------------+
SELECT FORMAT("%T", ARRAY_AGG(DISTINCT x)) AS array_agg
FROM UNNEST([2, 1, -2, 3, -2, 1, 2]) AS x;
+---------------+
| array_agg |
+---------------+
| [2, 1, -2, 3] |
+---------------+
SELECT FORMAT("%T", ARRAY_AGG(x IGNORE NULLS)) AS array_agg
FROM UNNEST([NULL, 1, -2, 3, -2, 1, NULL]) AS x;
+-------------------+
| array_agg |
+-------------------+
| [1, -2, 3, -2, 1] |
+-------------------+
SELECT FORMAT("%T", ARRAY_AGG(x ORDER BY ABS(x))) AS array_agg
FROM UNNEST([2, 1, -2, 3, -2, 1, 2]) AS x;
+-------------------------+
| array_agg |
+-------------------------+
| [1, 1, 2, -2, -2, 2, 3] |
+-------------------------+
SELECT FORMAT("%T", ARRAY_AGG(x LIMIT 5)) AS array_agg
FROM UNNEST([2, 1, -2, 3, -2, 1, 2]) AS x;
+-------------------+
| array_agg |
+-------------------+
| [2, 1, -2, 3, -2] |
+-------------------+
SELECT FORMAT("%T", ARRAY_AGG(DISTINCT x IGNORE NULLS ORDER BY x LIMIT 2)) AS array_agg
FROM UNNEST([NULL, 1, -2, 3, -2, 1, NULL]) AS x;
+-----------+
| array_agg |
+-----------+
| [-2, 1] |
+-----------+
SELECT
x,
FORMAT("%T", ARRAY_AGG(x) OVER (ORDER BY ABS(x))) AS array_agg
FROM UNNEST([2, 1, -2, 3, -2, 1, 2]) AS x;
+----+-------------------------+
| x | array_agg |
+----+-------------------------+
| 1 | [1, 1] |
| 1 | [1, 1] |
| 2 | [1, 1, 2, -2, -2, 2] |
| -2 | [1, 1, 2, -2, -2, 2] |
| -2 | [1, 1, 2, -2, -2, 2] |
| 2 | [1, 1, 2, -2, -2, 2] |
| 3 | [1, 1, 2, -2, -2, 2, 3] |
+----+-------------------------+ARRAY_CONCAT_AGG
ARRAY_CONCAT_AGG(expression [ORDER BY key [{ASC|DESC}] [, ... ]] [LIMIT n])Description
Concatenates elements from expression of type
ARRAY, returning a single
ARRAY as a result. This function ignores NULL input
arrays, but respects the NULL elements in non-NULL input arrays
(an error is raised, however, if an array in the final query result contains a NULL element).
Supported Argument Types
ARRAY
Optional Clauses
The clauses are applied in the following order:
-
ORDER BY: Specifies the order of the values.- For each sort key, the default sort direction is
ASC. - Array ordering is not supported, and thus the sort key cannot be the
same as
expression. - NULLs: In the context of the
ORDER BYclause, NULLs are the minimum possible value; that is, NULLs appear first inASCsorts and last inDESCsorts. - Floating point data types: see Floating Point Semantics on ordering and grouping.
- If
ORDER BYis not specified, the order of the elements in the output array is non-deterministic, which means you might receive a different result each time you use this function.
- For each sort key, the default sort direction is
-
LIMIT: Specifies the maximum number ofexpressioninputs in the result. The limit applies to the number of input arrays, not the number of elements in the arrays. An empty array counts as 1. A NULL array is not counted. The limitnmust be a constant INT64.
Returned Data Types
ARRAY
Returns NULL if there are zero input
rows or expression evaluates to NULL for all rows.
Examples
SELECT FORMAT("%T", ARRAY_CONCAT_AGG(x)) AS array_concat_agg FROM (
SELECT [NULL, 1, 2, 3, 4] AS x
UNION ALL SELECT NULL
UNION ALL SELECT [5, 6]
UNION ALL SELECT [7, 8, 9]
);
+-----------------------------------+
| array_concat_agg |
+-----------------------------------+
| [NULL, 1, 2, 3, 4, 5, 6, 7, 8, 9] |
+-----------------------------------+
SELECT FORMAT("%T", ARRAY_CONCAT_AGG(x ORDER BY ARRAY_LENGTH(x))) AS array_concat_agg FROM (
SELECT [NULL, 1, 2, 3, 4] AS x
UNION ALL SELECT NULL
UNION ALL SELECT [5, 6]
UNION ALL SELECT [7, 8, 9]
);
+-----------------------------------+
| array_concat_agg |
+-----------------------------------+
| [5, 6, 7, 8, 9, NULL, 1, 2, 3, 4] |
+-----------------------------------+
SELECT FORMAT("%T", ARRAY_CONCAT_AGG(x LIMIT 2)) AS array_concat_agg FROM (
SELECT [NULL, 1, 2, 3, 4] AS x
UNION ALL SELECT NULL
UNION ALL SELECT [5, 6]
UNION ALL SELECT [7, 8, 9]
);
+--------------------------+
| array_concat_agg |
+--------------------------+
| [NULL, 1, 2, 3, 4, 5, 6] |
+--------------------------+
SELECT FORMAT("%T", ARRAY_CONCAT_AGG(x ORDER BY ARRAY_LENGTH(x) LIMIT 2)) AS array_concat_agg FROM (
SELECT [NULL, 1, 2, 3, 4] AS x
UNION ALL SELECT NULL
UNION ALL SELECT [5, 6]
UNION ALL SELECT [7, 8, 9]
);
+------------------+
| array_concat_agg |
+------------------+
| [5, 6, 7, 8, 9] |
+------------------+AVG
AVG([DISTINCT] expression) [OVER (...)]Description
Returns the average of non-NULL input values, or NaN if the input contains a
NaN.
Supported Argument Types
Any numeric input type, such as INT64. Note that, for floating point input types, the return result is non-deterministic, which means you might receive a different result each time you use this function.
Optional Clauses
The clauses are applied in the following order:
-
OVER: Specifies a window. See Analytic Functions. This clause is currently incompatible with all other clauses withinAVG(). -
DISTINCT: Each distinct value ofexpressionis aggregated only once into the result.
Returned Data Types
- NUMERIC if the input type is NUMERIC.
- FLOAT64
Examples
SELECT AVG(x) as avg
FROM UNNEST([0, 2, NULL, 4, 4, 5]) as x;
+-----+
| avg |
+-----+
| 3 |
+-----+
SELECT AVG(DISTINCT x) AS avg
FROM UNNEST([0, 2, NULL, 4, 4, 5]) AS x;
+------+
| avg |
+------+
| 2.75 |
+------+
SELECT
x,
AVG(x) OVER (ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW) AS avg
FROM UNNEST([0, 2, NULL, 4, 4, 5]) AS x;
+------+------+
| x | avg |
+------+------+
| NULL | NULL |
| 0 | 0 |
| 2 | 1 |
| 4 | 3 |
| 4 | 4 |
| 5 | 4.5 |
+------+------+BIT_AND
BIT_AND(expression)Description
Performs a bitwise AND operation on expression and returns the result.
Supported Argument Types
- INT64
Returned Data Types
INT64
Examples
SELECT BIT_AND(x) as bit_and FROM UNNEST([0xF001, 0x00A1]) as x;
+---------+
| bit_and |
+---------+
| 1 |
+---------+BIT_OR
BIT_OR(expression)Description
Performs a bitwise OR operation on expression and returns the result.
Supported Argument Types
- INT64
Returned Data Types
INT64
Examples
SELECT BIT_OR(x) as bit_or FROM UNNEST([0xF001, 0x00A1]) as x;
+--------+
| bit_or |
+--------+
| 61601 |
+--------+BIT_XOR
BIT_XOR([DISTINCT] expression)Description
Performs a bitwise XOR operation on expression and returns the result.
Supported Argument Types
- INT64
Optional Clause
DISTINCT: Each distinct value of
expression is aggregated only once into the result.
Returned Data Types
INT64
Examples
SELECT BIT_XOR(x) AS bit_xor FROM UNNEST([5678, 1234]) AS x;
+---------+
| bit_xor |
+---------+
| 4860 |
+---------+
SELECT BIT_XOR(x) AS bit_xor FROM UNNEST([1234, 5678, 1234]) AS x;
+---------+
| bit_xor |
+---------+
| 5678 |
+---------+
SELECT BIT_XOR(DISTINCT x) AS bit_xor FROM UNNEST([1234, 5678, 1234]) AS x;
+---------+
| bit_xor |
+---------+
| 4860 |
+---------+COUNT
1.
COUNT(*) [OVER (...)]2.
COUNT([DISTINCT] expression) [OVER (...)]Description
- Returns the number of rows in the input.
- Returns the number of rows with
expressionevaluated to any value other thanNULL.
Supported Argument Types
expression can be any data type.
Optional Clauses
The clauses are applied in the following order:
-
OVER: Specifies a window. See Analytic Functions. -
DISTINCT: Each distinct value ofexpressionis aggregated only once into the result.
Return Data Types
INT64
Examples
SELECT
COUNT(*) AS count_star,
COUNT(x) AS count_x,
COUNT(DISTINCT x) AS count_dist_x
FROM UNNEST([1, 4, NULL, 4, 5]) AS x;
+------------+---------+--------------+
| count_star | count_x | count_dist_x |
+------------+---------+--------------+
| 5 | 4 | 3 |
+------------+---------+--------------+
SELECT
x,
COUNT(*) OVER (PARTITION BY MOD(x, 3)) AS count_star,
COUNT(x) OVER (PARTITION BY MOD(x, 3)) AS count_x,
COUNT(DISTINCT x) OVER (PARTITION BY MOD(x, 3)) AS count_dist_x
FROM UNNEST([1, 4, NULL, 4, 5]) AS x;
+------+------------+---------+--------------+
| x | count_star | count_x | count_dist_x |
+------+------------+---------+--------------+
| NULL | 1 | 0 | 0 |
| 1 | 3 | 3 | 2 |
| 4 | 3 | 3 | 2 |
| 4 | 3 | 3 | 2 |
| 5 | 1 | 1 | 1 |
+------+------------+---------+--------------+COUNTIF
COUNTIF(expression) [OVER (...)]Description
Returns the count of TRUE values for expression.
Returns 0 if there are zero input rows or expression evaluates to FALSE
for all rows.
Supported Argument Types
BOOL
Optional Clause
OVER: Specifies a window. See
Analytic Functions.
Return Data Types
INT64
Examples
SELECT COUNTIF(x<0) AS num_negative, COUNTIF(x>0) AS num_positive
FROM UNNEST([5, -2, 3, 6, -10, NULL, -7, 4, 0]) AS x;
+--------------+--------------+
| num_negative | num_positive |
+--------------+--------------+
| 3 | 4 |
+--------------+--------------+
SELECT
x,
COUNTIF(x<0) OVER (ORDER BY ABS(x) ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING) AS num_negative
FROM UNNEST([5, -2, 3, 6, -10, NULL, -7, 4, 0]) AS x;
+------+--------------+
| x | num_negative |
+------+--------------+
| NULL | 0 |
| 0 | 1 |
| -2 | 1 |
| 3 | 1 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| -7 | 2 |
| -10 | 2 |
+------+--------------+LOGICAL_AND
LOGICAL_AND(expression)Description
Returns the logical AND of all non-NULL expressions. Returns NULL if there
are zero input rows or expression evaluates to NULL for all rows.
Supported Argument Types
BOOL
Return Data Types
BOOL
Examples
SELECT LOGICAL_AND(x) as logical_and FROM UNNEST([true, false, true]) as x;
+-------------+
| logical_and |
+-------------+
| false |
+-------------+LOGICAL_OR
LOGICAL_OR(expression)Description
Returns the logical OR of all non-NULL expressions. Returns NULL if there
are zero input rows or expression evaluates to NULL for all rows.
Supported Argument Types
BOOL
Return Data Types
BOOL
Examples
SELECT LOGICAL_OR(x) as logical_or FROM UNNEST([true, false, true]) as x;
+------------+
| logical_or |
+------------+
| true |
+------------+MAX
MAX(expression) [OVER (...)]Description
Returns the maximum value of non-NULL expressions. Returns NULL if there
are zero input rows or expression evaluates to NULL for all rows.
Returns NaN if the input contains a NaN.
Supported Argument Types
Any data type except:
ARRAY
STRUCT
Optional Clause
OVER: Specifies a window. See
Analytic Functions.
Return Data Types
Same as the data type used as the input values.
Examples
SELECT MAX(x) AS max
FROM UNNEST([8, NULL, 37, 4, NULL, 55]) AS x;
+-----+
| max |
+-----+
| 55 |
+-----+
SELECT x, MAX(x) OVER (PARTITION BY MOD(x, 2)) AS max
FROM UNNEST([8, NULL, 37, 4, NULL, 55]) AS x;
+------+------+
| x | max |
+------+------+
| NULL | NULL |
| NULL | NULL |
| 8 | 8 |
| 4 | 8 |
| 37 | 55 |
| 55 | 55 |
+------+------+MIN
MIN(expression) [OVER (...)]Description
Returns the minimum value of non-NULL expressions. Returns NULL if there
are zero input rows or expression evaluates to NULL for all rows.
Returns NaN if the input contains a NaN.
Supported Argument Types
Any data type except:
ARRAY
STRUCT
Optional Clause
OVER: Specifies a window. See
Analytic Functions.
Return Data Types
Same as the data type used as the input values.
Examples
SELECT MIN(x) AS min
FROM UNNEST([8, NULL, 37, 4, NULL, 55]) AS x;
+-----+
| min |
+-----+
| 4 |
+-----+
SELECT x, MIN(x) OVER (PARTITION BY MOD(x, 2)) AS min
FROM UNNEST([8, NULL, 37, 4, NULL, 55]) AS x;
+------+------+
| x | min |
+------+------+
| NULL | NULL |
| NULL | NULL |
| 8 | 4 |
| 4 | 4 |
| 37 | 37 |
| 55 | 37 |
+------+------+STRING_AGG
STRING_AGG([DISTINCT] expression [, delimiter] [ORDER BY key [{ASC|DESC}] [, ... ]] [LIMIT n])
[OVER (...)]Description
Returns a value (either STRING or BYTES) obtained by concatenating non-null values.
If a delimiter is specified, concatenated values are separated by that
delimiter; otherwise, a comma is used as a delimiter.
Supported Argument Types
STRING BYTES
Optional Clauses
The clauses are applied in the following order:
-
OVER: Specifies a window. See Analytic Functions. This clause is currently incompatible with all other clauses withinSTRING_AGG(). -
DISTINCT: Each distinct value ofexpressionis aggregated only once into the result. -
ORDER BY: Specifies the order of the values.- For each sort key, the default sort direction is
ASC. - NULLs: In the context of the
ORDER BYclause, NULLs are the minimum possible value; that is, NULLs appear first inASCsorts and last inDESCsorts. - Floating point data types: see Floating Point Semantics on ordering and grouping.
- If
DISTINCTis also specified, then the sort key must be the same asexpression. - If
ORDER BYis not specified, the order of the elements in the output array is non-deterministic, which means you might receive a different result each time you use this function.
- For each sort key, the default sort direction is
-
LIMIT: Specifies the maximum number ofexpressioninputs in the result. The limit applies to the number of input strings, not the number of characters or bytes in the inputs. An empty string counts as 1. A NULL string is not counted. The limitnmust be a constant INT64.
Return Data Types
STRING BYTES
Examples
SELECT STRING_AGG(fruit) AS string_agg
FROM UNNEST(["apple", NULL, "pear", "banana", "pear"]) AS fruit;
+------------------------+
| string_agg |
+------------------------+
| apple,pear,banana,pear |
+------------------------+
SELECT STRING_AGG(fruit, " & ") AS string_agg
FROM UNNEST(["apple", NULL, "pear", "banana", "pear"]) AS fruit;
+------------------------------+
| string_agg |
+------------------------------+
| apple & pear & banana & pear |
+------------------------------+
SELECT STRING_AGG(DISTINCT fruit, " & ") AS string_agg
FROM UNNEST(["apple", NULL, "pear", "banana", "pear"]) AS fruit;
+-----------------------+
| string_agg |
+-----------------------+
| apple & banana & pear |
+-----------------------+
SELECT STRING_AGG(fruit, " & " ORDER BY LENGTH(fruit)) AS string_agg
FROM UNNEST(["apple", NULL, "pear", "banana", "pear"]) AS fruit;
+------------------------------+
| string_agg |
+------------------------------+
| pear & pear & apple & banana |
+------------------------------+
SELECT STRING_AGG(fruit, " & " LIMIT 2) AS string_agg
FROM UNNEST(["apple", NULL, "pear", "banana", "pear"]) AS fruit;
+--------------+
| string_agg |
+--------------+
| apple & pear |
+--------------+
SELECT STRING_AGG(DISTINCT fruit, " & " ORDER BY fruit DESC LIMIT 2) AS string_agg
FROM UNNEST(["apple", NULL, "pear", "banana", "pear"]) AS fruit;
+---------------+
| string_agg |
+---------------+
| pear & banana |
+---------------+
SELECT
fruit,
STRING_AGG(fruit, " & ") OVER (ORDER BY LENGTH(fruit)) AS string_agg
FROM UNNEST(["apple", NULL, "pear", "banana", "pear"]) AS fruit;
+--------+------------------------------+
| fruit | string_agg |
+--------+------------------------------+
| NULL | NULL |
| pear | pear & pear |
| pear | pear & pear |
| apple | pear & pear & apple |
| banana | pear & pear & apple & banana |
+--------+------------------------------+SUM
SUM([DISTINCT] expression) [OVER (...)]Description
Returns the sum of non-null values.
If the expression is a floating point value, the sum is non-deterministic, which means you might receive a different result each time you use this function.
Supported Argument Types
Any supported numeric data types.
Optional Clauses
The clauses are applied in the following order:
-
OVER: Specifies a window. See Analytic Functions. -
DISTINCT: Each distinct value ofexpressionis aggregated only once into the result.
Return Data Types
-
Returns INT64 if the input is an integer.
-
Returns NUMERIC if the input type is NUMERIC.
- Returns FLOAT64 if the input is a floating point value.
Returns NULL if the input contains only NULLs.
Returns Inf if the input contains Inf.
Returns -Inf if the input contains -Inf.
Returns NaN if the input contains a NaN.
Returns NaN if the input contains a combination of Inf and -Inf.
Examples
SELECT SUM(x) AS sum
FROM UNNEST([1, 2, 3, 4, 5, 4, 3, 2, 1]) AS x;
+-----+
| sum |
+-----+
| 25 |
+-----+
SELECT SUM(DISTINCT x) AS sum
FROM UNNEST([1, 2, 3, 4, 5, 4, 3, 2, 1]) AS x;
+-----+
| sum |
+-----+
| 15 |
+-----+
SELECT
x,
SUM(x) OVER (PARTITION BY MOD(x, 3)) AS sum
FROM UNNEST([1, 2, 3, 4, 5, 4, 3, 2, 1]) AS x;
+---+-----+
| x | sum |
+---+-----+
| 3 | 6 |
| 3 | 6 |
| 1 | 10 |
| 4 | 10 |
| 4 | 10 |
| 1 | 10 |
| 2 | 9 |
| 5 | 9 |
| 2 | 9 |
+---+-----+
SELECT
x,
SUM(DISTINCT x) OVER (PARTITION BY MOD(x, 3)) AS sum
FROM UNNEST([1, 2, 3, 4, 5, 4, 3, 2, 1]) AS x;
+---+-----+
| x | sum |
+---+-----+
| 3 | 3 |
| 3 | 3 |
| 1 | 5 |
| 4 | 5 |
| 4 | 5 |
| 1 | 5 |
| 2 | 7 |
| 5 | 7 |
| 2 | 7 |
+---+-----+Statistical Aggregate Functions
BigQuery supports the following statistical aggregate functions.
CORR
CORR(X1, X2) [OVER (...)]Description
Returns the Pearson coefficient
of correlation of a set of number pairs. For each number pair, the first number
is the dependent variable and the second number is the independent variable.
The return result is between -1 and 1. A result of 0 indicates no
correlation.
This function ignores any input pairs that contain one or more NULL values. If there are fewer than two input pairs without NULL values, this function returns NULL.
Supported Input Types
FLOAT64
Optional Clause
OVER: Specifies a window. See
Analytic Functions.
Return Data Type
FLOAT64
COVAR_POP
COVAR_POP(X1, X2) [OVER (...)]Description
Returns the population covariance of
a set of number pairs. The first number is the dependent variable; the second
number is the independent variable. The return result is between -Inf and
+Inf.
This function ignores any input pairs that contain one or more NULL values. If there is no input pair without NULL values, this function returns NULL. If there is exactly one input pair without NULL values, this function returns 0.
Supported Input Types
FLOAT64
Optional Clause
OVER: Specifies a window. See
Analytic Functions.
Return Data Type
FLOAT64
COVAR_SAMP
COVAR_SAMP(X1, X2) [OVER (...)]Description
Returns the sample covariance of a
set of number pairs. The first number is the dependent variable; the second
number is the independent variable. The return result is between -Inf and
+Inf.
This function ignores any input pairs that contain one or more NULL values. If there are fewer than two input pairs without NULL values, this function returns NULL.
Supported Input Types
FLOAT64
Optional Clause
OVER: Specifies a window. See
Analytic Functions.
Return Data Type
FLOAT64
STDDEV_POP
STDDEV_POP([DISTINCT] expression) [OVER (...)]Description
Returns the population (biased) standard deviation of the values. The return
result is between 0 and +Inf.
This function ignores any NULL inputs. If all inputs are ignored, this function returns NULL.
If this function receives a single non-NULL input, it returns 0.
Supported Input Types
FLOAT64
Optional Clauses
The clauses are applied in the following order:
-
OVER: Specifies a window. See Analytic Functions. This clause is currently incompatible with all other clauses withinSTDDEV_POP(). -
DISTINCT: Each distinct value ofexpressionis aggregated only once into the result.
Return Data Type
FLOAT64
STDDEV_SAMP
STDDEV_SAMP([DISTINCT] expression) [OVER (...)]Description
Returns the sample (unbiased) standard deviation of the values. The return
result is between 0 and +Inf.
This function ignores any NULL inputs. If there are fewer than two non-NULL inputs, this function returns NULL.
Supported Input Types
FLOAT64
Optional Clauses
The clauses are applied in the following order:
-
OVER: Specifies a window. See Analytic Functions. This clause is currently incompatible with all other clauses withinSTDDEV_SAMP(). -
DISTINCT: Each distinct value ofexpressionis aggregated only once into the result.
Return Data Type
FLOAT64
STDDEV
STDDEV([DISTINCT] expression) [OVER (...)]Description
An alias of STDDEV_SAMP.
VAR_POP
VAR_POP([DISTINCT] expression) [OVER (...)]Description
Returns the population (biased) variance of the values. The return result is
between 0 and +Inf.
This function ignores any NULL inputs. If all inputs are ignored, this function returns NULL.
If this function receives a single non-NULL input, it returns 0.
Supported Input Types
FLOAT64
Optional Clauses
The clauses are applied in the following order:
-
OVER: Specifies a window. See Analytic Functions. This clause is currently incompatible with all other clauses withinVAR_POP(). -
DISTINCT: Each distinct value ofexpressionis aggregated only once into the result.
Return Data Type
FLOAT64
VAR_SAMP
VAR_SAMP([DISTINCT] expression) [OVER (...)]Description
Returns the sample (unbiased) variance of the values. The return result is
between 0 and +Inf.
This function ignores any NULL inputs. If there are fewer than two non-NULL inputs, this function returns NULL.
Supported Input Types
FLOAT64
Optional Clauses
The clauses are applied in the following order:
-
OVER: Specifies a window. See Analytic Functions. This clause is currently incompatible with all other clauses withinVAR_SAMP(). -
DISTINCT: Each distinct value ofexpressionis aggregated only once into the result.
Return Data Type
FLOAT64
VARIANCE
VARIANCE([DISTINCT] expression) [OVER (...)]Description
An alias of VAR_SAMP.
Approximate Aggregate Functions
Approximate aggregate functions are scalable in terms of memory usage and time, but produce approximate results instead of exact results. For more background, see Approximate Aggregation.
APPROX_COUNT_DISTINCT
APPROX_COUNT_DISTINCT(expression)Description
Returns the approximate result for COUNT(DISTINCT expression). The value
returned is a statistical estimate—not necessarily the actual value.
This function is less accurate than COUNT(DISTINCT expression), but performs
better on huge input.
Supported Argument Types
Any data type except:
ARRAY
STRUCT
Returned Data Types
INT64
Examples
SELECT APPROX_COUNT_DISTINCT(x) as approx_distinct
FROM UNNEST([0, 1, 1, 2, 3, 5]) as x;
+-----------------+
| approx_distinct |
+-----------------+
| 5 |
+-----------------+APPROX_QUANTILES
APPROX_QUANTILES([DISTINCT] expression, number [{IGNORE|RESPECT} NULLS])Description
Returns the approximate boundaries for a group of expression values, where
number represents the number of quantiles to create. This function returns
an array of number + 1 elements, where the first element is the approximate
minimum and the last element is the approximate maximum.
Supported Argument Types
expression can be any supported data type except:
ARRAY
STRUCT
number must be INT64.
Optional Clauses
The clauses are applied in the following order:
-
DISTINCT: Each distinct value ofexpressionis aggregated only once into the result. -
IGNORE NULLSorRESPECT NULLS: IfIGNORE NULLSis specified or if neither is specified, the NULL values are excluded from the result. IfRESPECT NULLSis specified, the NULL values are included in the result (an error is raised, however, if an array in the final query result contains a NULL element).
Returned Data Types
An ARRAY of the type specified by the expression
parameter.
Returns NULL if there are zero input
rows or expression evaluates to NULL for all rows.
Examples
SELECT APPROX_QUANTILES(x, 2) AS approx_quantiles
FROM UNNEST([NULL, NULL, 1, 1, 1, 4, 5, 6, 7, 8, 9, 10]) AS x;
+------------------+
| approx_quantiles |
+------------------+
| [1, 5, 10] |
+------------------+
SELECT APPROX_QUANTILES(x, 100)[OFFSET(90)] AS percentile_90
FROM UNNEST([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) AS x;
+---------------+
| percentile_90 |
+---------------+
| 9 |
+---------------+
SELECT APPROX_QUANTILES(DISTINCT x, 2) AS approx_quantiles
FROM UNNEST([NULL, NULL, 1, 1, 1, 4, 5, 6, 7, 8, 9, 10]) AS x;
+------------------+
| approx_quantiles |
+------------------+
| [1, 6, 10] |
+------------------+
SELECT FORMAT("%T", APPROX_QUANTILES(x, 2 RESPECT NULLS)) AS approx_quantiles
FROM UNNEST([NULL, NULL, 1, 1, 1, 4, 5, 6, 7, 8, 9, 10]) AS x;
+------------------+
| approx_quantiles |
+------------------+
| [NULL, 4, 10] |
+------------------+
SELECT FORMAT("%T", APPROX_QUANTILES(DISTINCT x, 2 RESPECT NULLS)) AS approx_quantiles
FROM UNNEST([NULL, NULL, 1, 1, 1, 4, 5, 6, 7, 8, 9, 10]) AS x;
+------------------+
| approx_quantiles |
+------------------+
| [NULL, 6, 10] |
+------------------+APPROX_TOP_COUNT
APPROX_TOP_COUNT(expression, number)Description
Returns the approximate top elements of expression. The number parameter
specifies the number of elements returned.
Supported Argument Types
expression can be of any data type that the GROUP BY clause supports.
number must be INT64.
Returned Data Types
An ARRAY of type STRUCT.
The STRUCT contains two fields. The first field
(named value) contains an input value. The second field (named count)
contains an INT64 specifying the number of times the
value was returned.
Returns NULL if there are zero input rows.
Examples
SELECT APPROX_TOP_COUNT(x, 2) as approx_top_count
FROM UNNEST(["apple", "apple", "pear", "pear", "pear", "banana"]) as x;
+-------------------------+
| approx_top_count |
+-------------------------+
| [{pear, 3}, {apple, 2}] |
+-------------------------+NULL handling
APPROX_TOP_COUNT does not ignore NULLs in the input. For example:
SELECT APPROX_TOP_COUNT(x, 2) as approx_top_count
FROM UNNEST([NULL, "pear", "pear", "pear", "apple", NULL]) as x;
+------------------------+
| approx_top_count |
+------------------------+
| [{pear, 3}, {NULL, 2}] |
+------------------------+APPROX_TOP_SUM
APPROX_TOP_SUM(expression, weight, number)Description
Returns the approximate top elements of expression, based on the sum of an
assigned weight. The number parameter specifies the number of elements
returned.
If the weight input is negative or NaN, this function returns an error.
Supported Argument Types
expression can be of any data type that the GROUP BY clause supports.
weight must be one of the following:
- INT64
- FLOAT64
number must be INT64.
Returned Data Types
An ARRAY of type STRUCT.
The STRUCT contains two fields: value and sum.
The value field contains the value of the input expression. The sum field is
the same type asweight, and is the approximate sum of the input weight
associated with the value field.
Returns NULL if there are zero input rows.
Examples
SELECT APPROX_TOP_SUM(x, weight, 2) AS approx_top_sum FROM
UNNEST([
STRUCT("apple" AS x, 3 AS weight),
("pear", 2),
("apple", 0),
("banana", 5),
("pear", 4)
]);
+--------------------------+
| approx_top_sum |
+--------------------------+
| [{pear, 6}, {banana, 5}] |
+--------------------------+NULL handling
APPROX_TOP_SUM does not ignore NULL values for the expression and weight
parameters.
SELECT APPROX_TOP_SUM(x, weight, 2) AS approx_top_sum FROM
UNNEST([STRUCT("apple" AS x, NULL AS weight), ("pear", 0), ("pear", NULL)]);
+----------------------------+
| approx_top_sum |
+----------------------------+
| [{pear, 0}, {apple, NULL}] |
+----------------------------+SELECT APPROX_TOP_SUM(x, weight, 2) AS approx_top_sum FROM
UNNEST([STRUCT("apple" AS x, 0 AS weight), (NULL, 2)]);
+-------------------------+
| approx_top_sum |
+-------------------------+
| [{NULL, 2}, {apple, 0}] |
+-------------------------+SELECT APPROX_TOP_SUM(x, weight, 2) AS approx_top_sum FROM
UNNEST([STRUCT("apple" AS x, 0 AS weight), (NULL, NULL)]);
+----------------------------+
| approx_top_sum |
+----------------------------+
| [{apple, 0}, {NULL, NULL}] |
+----------------------------+HyperLogLog++ Functions
BigQuery supports the following approximate aggregate functions using the HyperLogLog++ algorithm. For an explanation of how approximate aggregate functions work, see Approximate Aggregation.
HLL_COUNT.INIT
HLL_COUNT.INIT(input [, precision])Description
A scalar function that takes one or more input values and aggregates them into
a HyperLogLog++ sketch. Each sketch
is represented using the BYTES data type. You can then merge sketches using
HLL_COUNT.MERGE or HLL_COUNT.MERGE_PARTIAL. If no merging is needed,
you can extract the final count of distinct values from the sketch using
HLL_COUNT.EXTRACT.
An input can be one of the following:
- INT64
- STRING
- BYTES
This function supports an optional parameter, precision. This parameter
defines the accuracy of the estimate at the cost of additional memory required
to process the sketches or store them on disk. The following table shows the
allowed precision values, the maximum sketch size per group, and confidence
interval (CI) of typical precisions:
| Precision | Max. Sketch Size (KiB) | 65% CI | 95% CI | 99% CI |
|---|---|---|---|---|
| 10 | 1 | ±1.63% | ±3.25% | ±6.50% |
| 11 | 2 | ±1.15% | ±2.30% | ±4.60% |
| 12 | 4 | ±0.81% | ±1.63% | ±3.25% |
| 13 | 8 | ±0.57% | ±1.15% | ±1.72% |
| 14 | 16 | ±0.41% | ±0.81% | ±1.22% |
| 15 (default) | 32 | ±0.29% | ±0.57% | ±0.86% |
| 16 | 64 | ±0.20% | ±0.41% | ±0.61% |
| 17 | 128 | ±0.14% | ±0.29% | ±0.43% |
| 18 | 256 | ±0.10% | ±0.20% | ±0.41% |
| 19 | 512 | ±0.07% | ±0.14% | ±0.29% |
| 20 | 1024 | ±0.05% | ±0.10% | ±0.20% |
| 21 | 2048 | ±0.04% | ±0.07% | ±0.14% |
| 22 | 4096 | ±0.03% | ±0.05% | ±0.10% |
| 23 | 8192 | ±0.02% | ±0.04% | ±0.07% |
| 24 | 16384 | ±0.01% | ±0.03% | ±0.05% |
If the input is NULL, this function returns NULL.
For more information, see HyperLogLog in Practice: Algorithmic Engineering of a State of The Art Cardinality Estimation Algorithm.
Supported input type
BYTES
Return type
BYTES
Example
SELECT
HLL_COUNT.INIT(respondent) AS respondents_hll,
flavor,
country
FROM UNNEST([
STRUCT(1 AS respondent, "Vanilla" AS flavor, "CH" AS country),
(1, "Chocolate", "CH"),
(2, "Chocolate", "US"),
(2, "Strawberry", "US")])
GROUP BY flavor, country;HLL_COUNT.MERGE
HLL_COUNT.MERGE(sketch)Description
An aggregate function that returns the cardinality of several HyperLogLog++ set sketches by computing their union.
Each sketch must have the same precision and be initialized on the same type.
Attempts to merge sketches with different precisions or for different types
results in an error. For example, you cannot merge a sketch initialized
from INT64 data with one initialized from STRING data.
This function ignores NULL values when merging sketches. If the merge happens
over zero rows or only over NULL values, the function returns 0.
Supported input types
BYTES
Return type
INT64
Example
SELECT HLL_COUNT.MERGE(respondents_hll) AS num_respondents, flavor
FROM (
SELECT
HLL_COUNT.INIT(respondent) AS respondents_hll,
flavor,
country
FROM UNNEST([
STRUCT(1 AS respondent, "Vanilla" AS flavor, "CH" AS country),
(1, "Chocolate", "CH"),
(2, "Chocolate", "US"),
(2, "Strawberry", "US")])
GROUP BY flavor, country)
GROUP BY flavor;HLL_COUNT.MERGE_PARTIAL
HLL_COUNT.MERGE_PARTIAL(sketch)Description
An aggregate function that takes one or more
HyperLogLog++ sketch
inputs and merges them into a new sketch.
This function returns NULL if there is no input or all inputs are NULL.
Supported input types
BYTES
Return type
BYTES
Example
SELECT HLL_COUNT.MERGE_PARTIAL(respondents_hll) AS num_respondents, flavor
FROM (
SELECT
HLL_COUNT.INIT(respondent) AS respondents_hll,
flavor,
country
FROM UNNEST([
STRUCT(1 AS respondent, "Vanilla" AS flavor, "CH" AS country),
(1, "Chocolate", "CH"),
(2, "Chocolate", "US"),
(2, "Strawberry", "US")])
GROUP BY flavor, country)
GROUP BY flavor;HLL_COUNT.EXTRACT
HLL_COUNT.EXTRACT(sketch)Description
A scalar function that extracts an cardinality estimate of a single HyperLogLog++ sketch.
If sketch is NULL, this function returns a cardinality estimate of 0.
Supported input types
BYTES
Return type
INT64
Example
SELECT
flavor,
country,
HLL_COUNT.EXTRACT(respondents_hll) AS num_respondents
FROM (
SELECT
HLL_COUNT.INIT(respondent) AS respondents_hll,
flavor,
country
FROM UNNEST([
STRUCT(1 AS respondent, "Vanilla" AS flavor, "CH" AS country),
(1, "Chocolate", "CH"),
(2, "Chocolate", "US"),
(2, "Strawberry", "US")])
GROUP BY flavor, country);
+------------+---------+-----------------+
| flavor | country | num_respondents |
+------------+---------+-----------------+
| Vanilla | CH | 1 |
| Chocolate | CH | 1 |
| Chocolate | US | 1 |
| Strawberry | US | 1 |
+------------+---------+-----------------+Numbering Functions
The following sections describe the numbering functions that BigQuery supports. Numbering functions are a subset of analytic functions. For an explanation of how analytic functions work, see Analytic Function Concepts. For a description of how numbering functions work, see the Numbering Function Concepts.
OVER clause requirements:
PARTITION BY: Optional.ORDER BY: Required, except forROW_NUMBER().window_frame_clause: Disallowed.
RANK
Description
Returns the ordinal (1-based) rank of each row within the ordered partition.
All peer rows receive the same rank value. The next row or set of peer rows
receives a rank value which increments by the number of peers with the previous
rank value, instead of DENSE_RANK, which always increments by 1.
Supported Argument Types
INT64
DENSE_RANK
Description
Returns the ordinal (1-based) rank of each row within the window partition. All peer rows receive the same rank value, and the subsequent rank value is incremented by one.
Supported Argument Types
INT64
PERCENT_RANK
Description
Return the percentile rank of a row defined as (RK-1)/(NR-1), where RK is
the RANK of the row and NR is the number of rows in the partition.
Returns 0 if NR=1.
Supported Argument Types
FLOAT64
CUME_DIST
Description
Return the relative rank of a row defined as NP/NR. NP is defined to be the number of rows that either precede or are peers with the current row. NR is the number of rows in the partition.
Supported Argument Types
FLOAT64
NTILE
NTILE(constant_integer_expression)Description
This function divides the rows into constant_integer_expression
buckets based on row ordering and returns the 1-based bucket number that is
assigned to each row. The number of rows in the buckets can differ by at most 1.
The remainder values (the remainder of number of rows divided by buckets) are
distributed one for each bucket, starting with bucket 1. If
constant_integer_expression evaluates to NULL, 0 or negative, an
error is provided.
Supported Argument Types
INT64
ROW_NUMBER
Description
Does not require the ORDER BY clause. Returns the sequential
row ordinal (1-based) of each row for each ordered partition. If the
ORDER BY clause is unspecified then the result is
non-deterministic.
Supported Argument Types
INT64
Bit Functions
BigQuery supports the following bit functions.
BIT_COUNT
BIT_COUNT(expression)Description
The input, expression, must be an
integer or BYTES.
Returns the number of bits that are set in the input expression.
For signed integers, this is the number of bits in two's complement form.
Return Data Type
INT64
Example
SELECT a, BIT_COUNT(a) AS a_bits, FORMAT("%T", b) as b, BIT_COUNT(b) AS b_bits
FROM UNNEST([
STRUCT(0 AS a, b'' AS b), (0, b'\x00'), (5, b'\x05'), (8, b'\x00\x08'),
(0xFFFF, b'\xFF\xFF'), (-2, b'\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFE'),
(-1, b'\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF'),
(NULL, b'\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF')
]) AS x;
+-------+--------+---------------------------------------------+--------+
| a | a_bits | b | b_bits |
+-------+--------+---------------------------------------------+--------+
| 0 | 0 | b"" | 0 |
| 0 | 0 | b"\x00" | 0 |
| 5 | 2 | b"\x05" | 2 |
| 8 | 1 | b"\x00\x08" | 1 |
| 65535 | 16 | b"\xff\xff" | 16 |
| -2 | 63 | b"\xff\xff\xff\xff\xff\xff\xff\xfe" | 63 |
| -1 | 64 | b"\xff\xff\xff\xff\xff\xff\xff\xff" | 64 |
| NULL | NULL | b"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" | 80 |
+-------+--------+---------------------------------------------+--------+Mathematical functions
All mathematical functions have the following behaviors:
- They return
NULLif any of the input parameters isNULL. - They return
NaNif any of the arguments isNaN.
ABS
ABS(X)Description
Computes absolute value. Returns an error if the argument is an integer and the
output value cannot be represented as the same type; this happens only for the
largest negative input value, which has no positive representation. Returns
+inf for a +/-inf argument.
SIGN
SIGN(X)Description
Returns -1, 0, or +1 for negative, zero and positive arguments respectively.
For floating point arguments, this function does not distinguish between
positive and negative zero. Returns NaN for a NaN argument.
IS_INF
IS_INF(X)Description
Returns TRUE if the value is positive or negative infinity. Returns
NULL for NULL inputs.
IS_NAN
IS_NAN(X)Description
Returns TRUE if the value is a NaN value. Returns NULL for NULL inputs.
IEEE_DIVIDE
IEEE_DIVIDE(X, Y)Description
Divides X by Y; this function never fails. Returns
FLOAT64. Unlike the division operator (/),
this function does not generate errors for division by zero or overflow.
Special cases:
- If the result overflows, returns
+/-inf. - If Y=0 and X=0, returns
NaN. - If Y=0 and X!=0, returns
+/-inf. - If X =
+/-infand Y =+/-inf, returnsNaN.
The behavior of IEEE_DIVIDE is further illustrated in the table below.
Special cases for IEEE_DIVIDE
The following table lists special cases for IEEE_DIVIDE.
| Numerator Data Type (X) | Denominator Data Type (Y) | Result Value |
|---|---|---|
| Anything except 0 | 0 | +/-inf |
| 0 | 0 | NaN |
| 0 | NaN |
NaN |
NaN |
0 | NaN |
+/-inf |
+/-inf |
NaN |
RAND
RAND()Description
Generates a pseudo-random value of type FLOAT64 in the range of [0, 1), inclusive of 0 and exclusive of 1.
SQRT
SQRT(X)Description
Computes the square root of X. Generates an error if X is less than 0. Returns
+inf if X is +inf.
POW
POW(X, Y)Description
Returns the value of X raised to the power of Y. If the result underflows and is not representable, then the function returns a value of zero. Returns an error if one of the following is true:
- X is a finite value less than 0 and Y is a noninteger
- X is 0 and Y is a finite value less than 0
The behavior of POW() is further illustrated in the table below.
POWER
POWER(X, Y)Description
Synonym of POW().
Special cases for POW(X, Y) and POWER(X, Y)
The following are special cases for POW(X, Y) and POWER(X, Y).
| X | Y | POW(X, Y) or POWER(X, Y) |
|---|---|---|
| 1.0 | Any value including NaN |
1.0 |
any including NaN |
0 | 1.0 |
| -1.0 | +/-inf |
1.0 |
| ABS(X) < 1 | -inf |
+inf |
| ABS(X) > 1 | -inf |
0 |
| ABS(X) < 1 | +inf |
0 |
| ABS(X) > 1 | +inf |
+inf |
-inf |
Y < 0 | 0 |
-inf |
Y > 0 | -inf if Y is an odd integer, +inf otherwise |
+inf |
Y < 0 | 0 |
+inf |
Y > 0 | +inf |
EXP
EXP(X)Description
Computes e to the power of X, also called the natural exponential function. If
the result underflows, this function returns a zero. Generates an error if the
result overflows. If X is +/-inf, then this function returns +inf or 0.
LN
LN(X)Description
Computes the natural logarithm of X. Generates an error if X is less than or
equal to zero. If X is +inf, then this function returns +inf.
LOG
LOG(X [, Y])Description
If only X is present, LOG is a synonym of LN. If Y is also present, LOG
computes the logarithm of X to base Y. Generates an error in these cases:
- X is less than or equal to zero
- Y is 1.0
- Y is less than or equal to zero.
The behavior of LOG(X, Y) is further illustrated in the table below.
Special cases for LOG(X, Y)
| X | Y | LOG(X, Y) |
|---|---|---|
-inf |
Any value | NaN |
| Any value | +inf |
NaN |
+inf |
0.0 Y < 1.0 | -inf |
+inf |
Y > 1.0 | +inf |
LOG10
LOG10(X)Description
Similar to LOG, but computes logarithm to base 10.
GREATEST
GREATEST(X1,...,XN)Description
Returns NULL if any of the inputs is NULL. Otherwise, returns NaN if any of
the inputs is NaN. Otherwise, returns the largest value among X1,...,XN
according to the < comparison.
LEAST
LEAST(X1,...,XN)Description
Returns NULL if any of the inputs is NULL. Returns NaN if any of the
inputs is NaN. Otherwise, returns the smallest value among X1,...,XN
according to the > comparison.
DIV
DIV(X, Y)Description
Returns the result of integer division of X by Y. Division by zero returns an error. Division by -1 may overflow. See the table below for possible result types.
SAFE_DIVIDE
SAFE_DIVIDE(X, Y)Description
Equivalent to the division operator (/), but returns
NULL if an error occurs, such as a division by zero error.
MOD
MOD(X, Y)Description
Modulo function: returns the remainder of the division of X by Y. Returned value has the same sign as X. An error is generated if Y is 0. See the table below for possible result types.
ROUND
ROUND(X [, N])Description
If only X is present, ROUND rounds X to the nearest integer. If N is present,
ROUND rounds X to N decimal places after the decimal point. If N is negative,
ROUND will round off digits to the left of the decimal point. Rounds halfway
cases away from zero. Generates an error if overflow occurs.
TRUNC
TRUNC(X [, N])Description
If only X is present, TRUNC rounds X to the nearest integer whose absolute
value is not greater than the absolute value of X. If N is also present, TRUNC
behaves like ROUND(X, N), but always rounds towards zero and never overflows.
CEIL
CEIL(X)Description
Returns the smallest integral value (with FLOAT64 type) that is not less than X.
CEILING
CEILING(X)Description
Synonym of CEIL(X)
FLOOR
FLOOR(X)Description
Returns the largest integral value (with FLOAT64 type) that is not greater than X.
Example rounding function behavior
Example behavior of BigQuery rounding functions:
| Input "X" | ROUND(X) | TRUNC(X) | CEIL(X) | FLOOR(X) |
|---|---|---|---|---|
| 2.0 | 2.0 | 2.0 | 2.0 | 2.0 |
| 2.3 | 2.0 | 2.0 | 3.0 | 2.0 |
| 2.8 | 3.0 | 2.0 | 3.0 | 2.0 |
| 2.5 | 3.0 | 2.0 | 3.0 | 2.0 |
| -2.3 | -2.0 | -2.0 | -2.0 | -3.0 |
| -2.8 | -3.0 | -2.0 | -2.0 | -3.0 |
| -2.5 | -3.0 | -2.0 | -2.0 | -3.0 |
| 0 | 0 | 0 | 0 | 0 |
+/-inf |
+/-inf |
+/-inf |
+/-inf |
+/-inf |
NaN |
NaN |
NaN |
NaN |
NaN |
COS
COS(X)Description
Computes cosine of X. Never fails.
COSH
COSH(X)Description
Computes the hyperbolic cosine of X. Generates an error if an overflow occurs.
ACOS
ACOS(X)Description
Computes the principal value of the arc cosine of X. The return value is in the range [0,]. Generates an error if X is a finite value outside of range [-1, 1].
ACOSH
ACOSH(X)Description
Computes the inverse hyperbolic cosine of X. Generates an error if X is a finite value less than 1.
SIN
SIN(X)Description
Computes the sine of X. Never fails.
SINH
SINH(X)Description
Computes the hyperbolic sine of X. Generates an error if an overflow occurs.
ASIN
ASIN(X)Description
Computes the principal value of the arc sine of X. The return value is in the range [-π/2,π/2]. Generates an error if X is a finite value outside of range [-1, 1].
ASINH
ASINH(X)Description
Computes the inverse hyperbolic sine of X. Does not fail.
TAN
TAN(X)Description
Computes tangent of X. Generates an error if an overflow occurs.
TANH
TANH(X)Description
Computes hyperbolic tangent of X. Does not fail.
ATAN
ATAN(X)Description
Computes the principal value of the arc tangent of X. The return value is in the range [-π/2,π/2]. Does not fail.
ATANH
ATANH(X)Description
Computes the inverse hyperbolic tangent of X. Generates an error if the absolute value of X is greater or equal 1.
ATAN2
ATAN2(Y, X)Description
Calculates the principal value of the arc tangent of Y/X using the signs of the two arguments to determine the quadrant. The return value is in the range [-π,π]. The behavior of this function is further illustrated in the table below.
Special cases for ATAN2()
| Y | X | ATAN2(Y, X) |
|---|---|---|
NaN |
Any value | NaN |
| Any value | NaN |
NaN |
| 0 | 0 | 0, π or -π depending on the sign of X and Y |
| Finite value | -inf |
π or -π depending on the sign of Y |
| Finite value | +inf |
0 |
+/-inf |
Finite value | π/2 or π/2 depending on the sign of Y |
+/-inf |
-inf |
¾π or -¾π depending on the sign of Y |
+/-inf |
+inf |
π/4 or -π/4 depending on the sign of Y |
Special cases for trigonometric and hyperbolic rounding functions
| X | COS(X) | COSH(X) | ACOS(X) | ACOSH(X) | SIN(X) | SINH(X) | ASIN(X) | ASINH(X) | TAN(X) | TANH(X) | ATAN(X) | ATANH(X) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
+/-inf |
NaN |
=+inf |
NaN |
=+inf |
NaN |
=+inf |
NaN |
=+inf |
NaN |
=+1.0 | π/2 | NaN |
-inf |
NaN |
=+inf |
NaN |
NaN |
NaN |
-inf |
NaN |
-inf |
NaN |
-1.0 | -π/2 | NaN |
NaN |
NaN |
NaN |
NaN |
NaN |
NaN |
NaN |
NaN |
NaN |
NaN |
NaN |
NaN |
NaN |
Navigation Functions
The following sections describe the navigation functions that BigQuery supports. Navigation functions are a subset of analytic functions. For an explanation of how analytic functions work, see Analytic Function Concepts. For an explanation of how navigation functions work, see Navigation Function Concepts.
FIRST_VALUE
FIRST_VALUE (value_expression [{RESPECT | IGNORE} NULLS])Description
Returns the value of the value_expression for the first row in the current
window frame.
This function includes NULL values in the calculation unless IGNORE NULLS is
present. If IGNORE NULLS is present, the function excludes NULL values from
the calculation.
Supported Argument Types
value_expression can be any data type that an expression can return.
Return Data Type
ANY
Examples
The following example computes the fastest time for each division.
WITH finishers AS
(SELECT 'Sophia Liu' as name,
TIMESTAMP '2016-10-18 2:51:45' as finish_time,
'F30-34' as division
UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 3:07:41', 'F30-34'
UNION ALL SELECT 'Carly Forte', TIMESTAMP '2016-10-18 3:08:58', 'F25-29'
UNION ALL SELECT 'Lauren Reasoner', TIMESTAMP '2016-10-18 3:10:14', 'F30-34')
SELECT name,
FORMAT_TIMESTAMP('%X', finish_time) AS finish_time,
division,
FORMAT_TIMESTAMP('%X', fastest_time) AS fastest_time,
TIMESTAMP_DIFF(finish_time, fastest_time, SECOND) AS delta_in_seconds
FROM (
SELECT name,
finish_time,
division,
FIRST_VALUE(finish_time)
OVER (PARTITION BY division ORDER BY finish_time ASC
ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS fastest_time
FROM finishers);
+-----------------+-------------+----------+--------------+------------------+
| name | finish_time | division | fastest_time | delta_in_seconds |
+-----------------+-------------+----------+--------------+------------------+
| Carly Forte | 03:08:58 | F25-29 | 03:08:58 | 0 |
| Sophia Liu | 02:51:45 | F30-34 | 02:51:45 | 0 |
| Nikki Leith | 02:59:01 | F30-34 | 02:51:45 | 436 |
| Jen Edwards | 03:06:36 | F30-34 | 02:51:45 | 891 |
| Meghan Lederer | 03:07:41 | F30-34 | 02:51:45 | 956 |
| Lauren Reasoner | 03:10:14 | F30-34 | 02:51:45 | 1109 |
| Lisa Stelzner | 02:54:11 | F35-39 | 02:54:11 | 0 |
| Lauren Matthews | 03:01:17 | F35-39 | 02:54:11 | 426 |
| Desiree Berry | 03:05:42 | F35-39 | 02:54:11 | 691 |
| Suzy Slane | 03:06:24 | F35-39 | 02:54:11 | 733 |
+-----------------+-------------+----------+--------------+------------------+LAST_VALUE
LAST_VALUE (value_expression [{RESPECT | IGNORE} NULLS])Description
Returns the value of the value_expression for the last row in the current
window frame.
This function includes NULL values in the calculation unless IGNORE NULLS is
present. If IGNORE NULLS is present, the function excludes NULL values from
the calculation.
Supported Argument Types
value_expression can be any data type that an expression can return.
Return Data Type
ANY
Examples
The following example computes the slowest time for each division.
WITH finishers AS
(SELECT 'Sophia Liu' as name,
TIMESTAMP '2016-10-18 2:51:45' as finish_time,
'F30-34' as division
UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 3:07:41', 'F30-34'
UNION ALL SELECT 'Carly Forte', TIMESTAMP '2016-10-18 3:08:58', 'F25-29'
UNION ALL SELECT 'Lauren Reasoner', TIMESTAMP '2016-10-18 3:10:14', 'F30-34')
SELECT name,
FORMAT_TIMESTAMP('%X', finish_time) AS finish_time,
division,
FORMAT_TIMESTAMP('%X', slowest_time) AS slowest_time,
TIMESTAMP_DIFF(slowest_time, finish_time, SECOND) AS delta_in_seconds
FROM (
SELECT name,
finish_time,
division,
LAST_VALUE(finish_time)
OVER (PARTITION BY division ORDER BY finish_time ASC
ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS slowest_time
FROM finishers);
+-----------------+-------------+----------+--------------+------------------+
| name | finish_time | division | slowest_time | delta_in_seconds |
+-----------------+-------------+----------+--------------+------------------+
| Carly Forte | 03:08:58 | F25-29 | 03:08:58 | 0 |
| Sophia Liu | 02:51:45 | F30-34 | 03:10:14 | 1109 |
| Nikki Leith | 02:59:01 | F30-34 | 03:10:14 | 673 |
| Jen Edwards | 03:06:36 | F30-34 | 03:10:14 | 218 |
| Meghan Lederer | 03:07:41 | F30-34 | 03:10:14 | 153 |
| Lauren Reasoner | 03:10:14 | F30-34 | 03:10:14 | 0 |
| Lisa Stelzner | 02:54:11 | F35-39 | 03:06:24 | 733 |
| Lauren Matthews | 03:01:17 | F35-39 | 03:06:24 | 307 |
| Desiree Berry | 03:05:42 | F35-39 | 03:06:24 | 42 |
| Suzy Slane | 03:06:24 | F35-39 | 03:06:24 | 0 |
+-----------------+-------------+----------+--------------+------------------+NTH_VALUE
NTH_VALUE (value_expression, constant_integer_expression [{RESPECT | IGNORE} NULLS])Description
Returns the value of value_expression at the Nth row of the current window
frame, where Nth is defined by constant_integer_expression. Returns NULL if
there is no such row.
This function includes NULL values in the calculation unless IGNORE NULLS is
present. If IGNORE NULLS is present, the function excludes NULL values from
the calculation.
Supported Argument Types
value_expressioncan be any data type that can be returned from an expression.constant_integer_expressioncan be any constant expression that returns an integer.
Return Data Type
ANY
Examples
WITH finishers AS
(SELECT 'Sophia Liu' as name,
TIMESTAMP '2016-10-18 2:51:45' as finish_time,
'F30-34' as division
UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 3:07:41', 'F30-34'
UNION ALL SELECT 'Carly Forte', TIMESTAMP '2016-10-18 3:08:58', 'F25-29'
UNION ALL SELECT 'Lauren Reasoner', TIMESTAMP '2016-10-18 3:10:14', 'F30-34')
SELECT name,
FORMAT_TIMESTAMP('%X', finish_time) AS finish_time,
division,
FORMAT_TIMESTAMP('%X', fastest_time) AS fastest_time,
FORMAT_TIMESTAMP('%X', second_fastest) AS second_fastest
FROM (
SELECT name,
finish_time,
division,finishers,
FIRST_VALUE(finish_time)
OVER w1 AS fastest_time,
NTH_VALUE(finish_time, 2)
OVER w1 as second_fastest
FROM finishers
WINDOW w1 AS (
PARTITION BY division ORDER BY finish_time ASC
ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING));
+-----------------+-------------+----------+--------------+----------------+
| name | finish_time | division | fastest_time | second_fastest |
+-----------------+-------------+----------+--------------+----------------+
| Carly Forte | 03:08:58 | F25-29 | 03:08:58 | NULL |
| Sophia Liu | 02:51:45 | F30-34 | 02:51:45 | 02:59:01 |
| Nikki Leith | 02:59:01 | F30-34 | 02:51:45 | 02:59:01 |
| Jen Edwards | 03:06:36 | F30-34 | 02:51:45 | 02:59:01 |
| Meghan Lederer | 03:07:41 | F30-34 | 02:51:45 | 02:59:01 |
| Lauren Reasoner | 03:10:14 | F30-34 | 02:51:45 | 02:59:01 |
| Lisa Stelzner | 02:54:11 | F35-39 | 02:54:11 | 03:01:17 |
| Lauren Matthews | 03:01:17 | F35-39 | 02:54:11 | 03:01:17 |
| Desiree Berry | 03:05:42 | F35-39 | 02:54:11 | 03:01:17 |
| Suzy Slane | 03:06:24 | F35-39 | 02:54:11 | 03:01:17 |
+-----------------+-------------+----------+--------------+----------------+LEAD
LEAD (value_expression[, offset [, default_expression]])Description
Returns the value of the value_expression on a subsequent row. Changing the
offset value changes which subsequent row is returned; the default value is
1, indicating the next row in the window frame. An error occurs if offset is
NULL or a negative value.
The optional default_expression is used if there isn't a row in the window
frame at the specified offset. This expression must be a constant expression and
its type must be implicitly coercible to the type of value_expression. If left
unspecified, default_expression defaults to NULL.
Supported Argument Types
value_expressioncan be any data type that can be returned from an expression.offsetmust be a non-negative integer literal or parameter.default_expressionmust be compatible with the value expression type.
Return Data Type
ANY
Examples
The following example illustrates a basic use of the LEAD function.
WITH finishers AS
(SELECT 'Sophia Liu' as name,
TIMESTAMP '2016-10-18 2:51:45' as finish_time,
'F30-34' as division
UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 3:07:41', 'F30-34'
UNION ALL SELECT 'Carly Forte', TIMESTAMP '2016-10-18 3:08:58', 'F25-29'
UNION ALL SELECT 'Lauren Reasoner', TIMESTAMP '2016-10-18 3:10:14', 'F30-34')
SELECT name,
finish_time,
division,
LEAD(name)
OVER (PARTITION BY division ORDER BY finish_time ASC) AS followed_by
FROM finishers;
+-----------------+-------------+----------+-----------------+
| name | finish_time | division | followed_by |
+-----------------+-------------+----------+-----------------+
| Carly Forte | 03:08:58 | F25-29 | NULL |
| Sophia Liu | 02:51:45 | F30-34 | Nikki Leith |
| Nikki Leith | 02:59:01 | F30-34 | Jen Edwards |
| Jen Edwards | 03:06:36 | F30-34 | Meghan Lederer |
| Meghan Lederer | 03:07:41 | F30-34 | Lauren Reasoner |
| Lauren Reasoner | 03:10:14 | F30-34 | NULL |
| Lisa Stelzner | 02:54:11 | F35-39 | Lauren Matthews |
| Lauren Matthews | 03:01:17 | F35-39 | Desiree Berry |
| Desiree Berry | 03:05:42 | F35-39 | Suzy Slane |
| Suzy Slane | 03:06:24 | F35-39 | NULL |
+-----------------+-------------+----------+-----------------+This next example uses the optional offset parameter.
WITH finishers AS
(SELECT 'Sophia Liu' as name,
TIMESTAMP '2016-10-18 2:51:45' as finish_time,
'F30-34' as division
UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 3:07:41', 'F30-34'
UNION ALL SELECT 'Carly Forte', TIMESTAMP '2016-10-18 3:08:58', 'F25-29'
UNION ALL SELECT 'Lauren Reasoner', TIMESTAMP '2016-10-18 3:10:14', 'F30-34')
SELECT name,
finish_time,
division,
LEAD(name, 2)
OVER (PARTITION BY division ORDER BY finish_time ASC) AS two_runners_back
FROM finishers;
+-----------------+-------------+----------+------------------+
| name | finish_time | division | two_runners_back |
+-----------------+-------------+----------+------------------+
| Carly Forte | 03:08:58 | F25-29 | NULL |
| Sophia Liu | 02:51:45 | F30-34 | Jen Edwards |
| Nikki Leith | 02:59:01 | F30-34 | Meghan Lederer |
| Jen Edwards | 03:06:36 | F30-34 | Lauren Reasoner |
| Meghan Lederer | 03:07:41 | F30-34 | NULL |
| Lauren Reasoner | 03:10:14 | F30-34 | NULL |
| Lisa Stelzner | 02:54:11 | F35-39 | Desiree Berry |
| Lauren Matthews | 03:01:17 | F35-39 | Suzy Slane |
| Desiree Berry | 03:05:42 | F35-39 | NULL |
| Suzy Slane | 03:06:24 | F35-39 | NULL |
+-----------------+-------------+----------+------------------+The following example replaces NULL values with a default value.
WITH finishers AS
(SELECT 'Sophia Liu' as name,
TIMESTAMP '2016-10-18 2:51:45' as finish_time,
'F30-34' as division
UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 3:07:41', 'F30-34'
UNION ALL SELECT 'Carly Forte', TIMESTAMP '2016-10-18 3:08:58', 'F25-29'
UNION ALL SELECT 'Lauren Reasoner', TIMESTAMP '2016-10-18 3:10:14', 'F30-34')
SELECT name,
finish_time,
division,
LEAD(name, 2, 'Nobody')
OVER (PARTITION BY division ORDER BY finish_time ASC) AS two_runners_back
FROM finishers;
+-----------------+-------------+----------+------------------+
| name | finish_time | division | two_runners_back |
+-----------------+-------------+----------+------------------+
| Carly Forte | 03:08:58 | F25-29 | Nobody |
| Sophia Liu | 02:51:45 | F30-34 | Jen Edwards |
| Nikki Leith | 02:59:01 | F30-34 | Meghan Lederer |
| Jen Edwards | 03:06:36 | F30-34 | Lauren Reasoner |
| Meghan Lederer | 03:07:41 | F30-34 | Nobody |
| Lauren Reasoner | 03:10:14 | F30-34 | Nobody |
| Lisa Stelzner | 02:54:11 | F35-39 | Desiree Berry |
| Lauren Matthews | 03:01:17 | F35-39 | Suzy Slane |
| Desiree Berry | 03:05:42 | F35-39 | Nobody |
| Suzy Slane | 03:06:24 | F35-39 | Nobody |
+-----------------+-------------+----------+------------------+LAG
LAG (value_expression[, offset [, default_expression]])Description
Returns the value of the value_expression on a preceding row. Changing the
offset value changes which preceding row is returned; the default value is
1, indicating the previous row in the window frame. An error occurs if
offset is NULL or a negative value.
The optional default_expression is used if there isn't a row in the window
frame at the specified offset. This expression must be a constant expression and
its type must be implicitly coercible to the type of value_expression. If left
unspecified, default_expression defaults to NULL.
Supported Argument Types
value_expressioncan be any data type that can be returned from an expression.offsetmust be a non-negative integer literal or parameter.default_expressionmust be compatible with the value expression type.
Return Data Type
ANY
Examples
The following example illustrates a basic use of the LAG function.
WITH finishers AS
(SELECT 'Sophia Liu' as name,
TIMESTAMP '2016-10-18 2:51:45' as finish_time,
'F30-34' as division
UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 3:07:41', 'F30-34'
UNION ALL SELECT 'Carly Forte', TIMESTAMP '2016-10-18 3:08:58', 'F25-29'
UNION ALL SELECT 'Lauren Reasoner', TIMESTAMP '2016-10-18 3:10:14', 'F30-34')
SELECT name,
finish_time,
division,
LAG(name)
OVER (PARTITION BY division ORDER BY finish_time ASC) AS preceding_runner
FROM finishers;
+-----------------+-------------+----------+------------------+
| name | finish_time | division | preceding_runner |
+-----------------+-------------+----------+------------------+
| Carly Forte | 03:08:58 | F25-29 | NULL |
| Sophia Liu | 02:51:45 | F30-34 | NULL |
| Nikki Leith | 02:59:01 | F30-34 | Sophia Liu |
| Jen Edwards | 03:06:36 | F30-34 | Nikki Leith |
| Meghan Lederer | 03:07:41 | F30-34 | Jen Edwards |
| Lauren Reasoner | 03:10:14 | F30-34 | Meghan Lederer |
| Lisa Stelzner | 02:54:11 | F35-39 | NULL |
| Lauren Matthews | 03:01:17 | F35-39 | Lisa Stelzner |
| Desiree Berry | 03:05:42 | F35-39 | Lauren Matthews |
| Suzy Slane | 03:06:24 | F35-39 | Desiree Berry |
+-----------------+-------------+----------+------------------+This next example uses the optional offset parameter.
WITH finishers AS
(SELECT 'Sophia Liu' as name,
TIMESTAMP '2016-10-18 2:51:45' as finish_time,
'F30-34' as division
UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 3:07:41', 'F30-34'
UNION ALL SELECT 'Carly Forte', TIMESTAMP '2016-10-18 3:08:58', 'F25-29'
UNION ALL SELECT 'Lauren Reasoner', TIMESTAMP '2016-10-18 3:10:14', 'F30-34')
SELECT name,
finish_time,
division,
LAG(name, 2)
OVER (PARTITION BY division ORDER BY finish_time ASC) AS two_runners_ahead
FROM finishers;
+-----------------+-------------+----------+-------------------+
| name | finish_time | division | two_runners_ahead |
+-----------------+-------------+----------+-------------------+
| Carly Forte | 03:08:58 | F25-29 | NULL |
| Sophia Liu | 02:51:45 | F30-34 | NULL |
| Nikki Leith | 02:59:01 | F30-34 | NULL |
| Jen Edwards | 03:06:36 | F30-34 | Sophia Liu |
| Meghan Lederer | 03:07:41 | F30-34 | Nikki Leith |
| Lauren Reasoner | 03:10:14 | F30-34 | Jen Edwards |
| Lisa Stelzner | 02:54:11 | F35-39 | NULL |
| Lauren Matthews | 03:01:17 | F35-39 | NULL |
| Desiree Berry | 03:05:42 | F35-39 | Lisa Stelzner |
| Suzy Slane | 03:06:24 | F35-39 | Lauren Matthews |
+-----------------+-------------+----------+-------------------+The following example replaces NULL values with a default value.
WITH finishers AS
(SELECT 'Sophia Liu' as name,
TIMESTAMP '2016-10-18 2:51:45' as finish_time,
'F30-34' as division
UNION ALL SELECT 'Lisa Stelzner', TIMESTAMP '2016-10-18 2:54:11', 'F35-39'
UNION ALL SELECT 'Nikki Leith', TIMESTAMP '2016-10-18 2:59:01', 'F30-34'
UNION ALL SELECT 'Lauren Matthews', TIMESTAMP '2016-10-18 3:01:17', 'F35-39'
UNION ALL SELECT 'Desiree Berry', TIMESTAMP '2016-10-18 3:05:42', 'F35-39'
UNION ALL SELECT 'Suzy Slane', TIMESTAMP '2016-10-18 3:06:24', 'F35-39'
UNION ALL SELECT 'Jen Edwards', TIMESTAMP '2016-10-18 3:06:36', 'F30-34'
UNION ALL SELECT 'Meghan Lederer', TIMESTAMP '2016-10-18 3:07:41', 'F30-34'
UNION ALL SELECT 'Carly Forte', TIMESTAMP '2016-10-18 3:08:58', 'F25-29'
UNION ALL SELECT 'Lauren Reasoner', TIMESTAMP '2016-10-18 3:10:14', 'F30-34')
SELECT name,
finish_time,
division,
LAG(name, 2, 'Nobody')
OVER (PARTITION BY division ORDER BY finish_time ASC) AS two_runners_ahead
FROM finishers;
+-----------------+-------------+----------+-------------------+
| name | finish_time | division | two_runners_ahead |
+-----------------+-------------+----------+-------------------+
| Carly Forte | 03:08:58 | F25-29 | Nobody |
| Sophia Liu | 02:51:45 | F30-34 | Nobody |
| Nikki Leith | 02:59:01 | F30-34 | Nobody |
| Jen Edwards | 03:06:36 | F30-34 | Sophia Liu |
| Meghan Lederer | 03:07:41 | F30-34 | Nikki Leith |
| Lauren Reasoner | 03:10:14 | F30-34 | Jen Edwards |
| Lisa Stelzner | 02:54:11 | F35-39 | Nobody |
| Lauren Matthews | 03:01:17 | F35-39 | Nobody |
| Desiree Berry | 03:05:42 | F35-39 | Lisa Stelzner |
| Suzy Slane | 03:06:24 | F35-39 | Lauren Matthews |
+-----------------+-------------+----------+-------------------+PERCENTILE_CONT
PERCENTILE_CONT (value_expression, percentile [{RESPECT | IGNORE} NULLS])Description
Computes the specified percentile value for the value_expression, with linear interpolation.
This function ignores NULL values if RESPECT NULLS is absent. If RESPECT
NULLS is present:
- Interpolation between two
NULLvalues returnsNULL. - Interpolation between a
NULLvalue and a non-NULLvalue returns the non-NULLvalue.
Supported Argument Types
value_expressionis a numeric expression.percentileis aDOUBLEliteral in the range[0, 1].
Return Data Type
DOUBLE
Examples
The following example computes the value for some percentiles from a column of values while ignoring nulls.
SELECT
PERCENTILE_CONT(x, 0) OVER() AS min,
PERCENTILE_CONT(x, 0.01) OVER() AS percentile1,
PERCENTILE_CONT(x, 0.5) OVER() AS median,
PERCENTILE_CONT(x, 0.9) OVER() AS percentile90,
PERCENTILE_CONT(x, 1) OVER() AS max
FROM UNNEST([0, 3, NULL, 1, 2]) AS x LIMIT 1;
+-----+-------------+--------+--------------+-----+
| min | percentile1 | median | percentile90 | max |
+-----+-------------+--------+--------------+-----+
| 0 | 0.03 | 1.5 | 2.7 | 3 |
+-----+-------------+--------+--------------+-----+The following example computes the value for some percentiles from a column of values while respecting nulls.
SELECT
PERCENTILE_CONT(x, 0 RESPECT NULLS) OVER() AS min,
PERCENTILE_CONT(x, 0.01 RESPECT NULLS) OVER() AS percentile1,
PERCENTILE_CONT(x, 0.5 RESPECT NULLS) OVER() AS median,
PERCENTILE_CONT(x, 0.9 RESPECT NULLS) OVER() AS percentile90,
PERCENTILE_CONT(x, 1 RESPECT NULLS) OVER() AS max
FROM UNNEST([0, 3, NULL, 1, 2]) AS x LIMIT 1;
+------+-------------+--------+--------------+-----+
| min | percentile1 | median | percentile90 | max |
+------+-------------+--------+--------------+-----+
| NULL | 0 | 1 | 2.6 | 3 |
+------+-------------+--------+--------------+-----+PERCENTILE_DISC
PERCENTILE_DISC (value_expression, percentile [{RESPECT | IGNORE} NULLS])Description
Computes the specified percentile value for a discrete value_expression. The
returned value is the first sorted value of value_expression with cumulative
distribution greater than or equal to the given percentile value.
This function ignores NULL values unless RESPECT NULLS is present.
Supported Argument Types
value_expressioncan be any orderable type.percentileis aDOUBLEliteral in the range[0, 1].
Return Data Type
ANY
Examples
The following example computes the value for some percentiles from a column of values while ignoring nulls.
SELECT
x,
PERCENTILE_DISC(x, 0) OVER() AS min,
PERCENTILE_DISC(x, 0.5) OVER() AS median,
PERCENTILE_DISC(x, 1) OVER() AS max
FROM UNNEST(['c', NULL, 'b', 'a']) AS x;
+------+-----+--------+-----+
| x | min | median | max |
+------+-----+--------+-----+
| c | a | b | c |
| NULL | a | b | c |
| b | a | b | c |
| a | a | b | c |
+------+-----+--------+-----+The following example computes the value for some percentiles from a column of values while respecting nulls.
SELECT
x,
PERCENTILE_DISC(x, 0 RESPECT NULLS) OVER() AS min,
PERCENTILE_DISC(x, 0.5 RESPECT NULLS) OVER() AS median,
PERCENTILE_DISC(x, 1 RESPECT NULLS) OVER() AS max
FROM UNNEST(['c', NULL, 'b', 'a']) AS x;
+------+------+--------+-----+
| x | min | median | max |
+------+------+--------+-----+
| c | NULL | a | c |
| NULL | NULL | a | c |
| b | NULL | a | c |
| a | NULL | a | c |
+------+------+--------+-----+Aggregate Analytic Functions
The following sections describe the aggregate analytic functions that BigQuery supports. For an explanation of how analytic functions work, see Analytic Function Concepts. For an explanation of how aggregate analytic functions work, see Aggregate Analytic Function Concepts.
BigQuery supports the following aggregate functions as analytic functions:
OVER clause requirements:
PARTITION BY: Optional.ORDER BY: Optional. Disallowed ifDISTINCTis present.window_frame_clause: Optional. Disallowed ifDISTINCTis present.
Example:
COUNT(*) OVER (ROWS UNBOUNDED PRECEDING)SUM(DISTINCT x) OVER ()Hash functions
FARM_FINGERPRINT
FARM_FINGERPRINT(value)Description
Computes the fingerprint of the STRING or BYTES input using the Fingerprint64
function from the
open-source FarmHash library. The output
of this function for a particular input will never change.
Return type
INT64
Examples
WITH example AS (
SELECT 1 AS x, "foo" AS y, true AS z UNION ALL
SELECT 2 AS x, "apple" AS y, false AS z UNION ALL
SELECT 3 AS x, "" AS y, true AS z
)
SELECT
*,
FARM_FINGERPRINT(CONCAT(CAST(x AS STRING), y, CAST(z AS STRING)))
AS row_fingerprint
FROM example;
+---+-------+-------+----------------------+
| x | y | z | row_fingerprint |
+---+-------+-------+----------------------+
| 1 | foo | true | -1541654101129638711 |
| 2 | apple | false | 2794438866806483259 |
| 3 | | true | -4880158226897771312 |
+---+-------+-------+----------------------+MD5
MD5(input)Description
Computes the hash of the input using the MD5 algorithm. The input can either be STRING or BYTES. The string version treats the input as an array of bytes.
This function returns 16 bytes.
Return type
BYTES
Example
SELECT MD5("Hello World") as md5;
+-------------------------------------------------+
| md5 |
+-------------------------------------------------+
| \xb1\n\x8d\xb1d\xe0uA\x05\xb7\xa9\x9b\xe7.?\xe5 |
+-------------------------------------------------+SHA1
SHA1(input)Description
Computes the hash of the input using the SHA-1 algorithm. The input can either be STRING or BYTES. The string version treats the input as an array of bytes.
This function returns 20 bytes.
Return type
BYTES
Example
SELECT SHA1("Hello World") as sha1;
+-----------------------------------------------------------+
| sha1 |
+-----------------------------------------------------------+
| \nMU\xa8\xd7x\xe5\x02/\xabp\x19w\xc5\xd8@\xbb\xc4\x86\xd0 |
+-----------------------------------------------------------+SHA256
SHA256(input)Description
Computes the hash of the input using the SHA-256 algorithm. The input can either be STRING or BYTES. The string version treats the input as an array of bytes.
This function returns 32 bytes.
Return type
BYTES
Example
SELECT SHA256("Hello World") as sha256;SHA512
SHA512(input)Description
Computes the hash of the input using the SHA-512 algorithm. The input can either be STRING or BYTES. The string version treats the input as an array of bytes.
This function returns 64 bytes.
Return type
BYTES
Example
SELECT SHA512("Hello World") as sha512;String functions
These string functions work on two different values: STRING and BYTES data types. STRING values must be well-formed UTF-8.
Functions that return position values, such as STRPOS, encode those
positions as INT64. The value 1 refers to the first
character (or byte), 2 refers to the second, and so on. The value 0
indicates an invalid index. When working on
STRING types, the returned positions refer to
character positions.
All string comparisons are done byte-by-byte, without regard to Unicode canonical equivalence.
BYTE_LENGTH
BYTE_LENGTH(value)Description
Returns the length of the value in bytes, regardless of whether the type of the value is STRING or BYTES.
Return type
INT64
Examples
WITH example AS
(SELECT "абвгд" AS characters, b"абвгд" AS bytes)
SELECT
characters,
BYTE_LENGTH(characters) AS string_example,
bytes,
BYTE_LENGTH(bytes) AS bytes_example
FROM example;
+------------+----------------+-------+---------------+
| characters | string_example | bytes | bytes_example |
+------------+----------------+-------+---------------+
| абвгд | 10 | абвгд | 10 |
+------------+----------------+-------+---------------+CHAR_LENGTH
CHAR_LENGTH(value)Description
Returns the length of the STRING in characters.
Return type
INT64
Examples
WITH example AS
(SELECT "абвгд" AS characters)
SELECT
characters,
CHAR_LENGTH(characters) AS char_length_example
FROM example;
+------------+---------------------+
| characters | char_length_example |
+------------+---------------------+
| абвгд | 5 |
+------------+---------------------+CHARACTER_LENGTH
CHARACTER_LENGTH(value)Description
Synonym for CHAR_LENGTH.
Return type
INT64
Examples
WITH example AS
(SELECT "абвгд" AS characters)
SELECT
characters,
CHARACTER_LENGTH(characters) AS char_length_example
FROM example;
+------------+---------------------+
| characters | char_length_example |
+------------+---------------------+
| абвгд | 5 |
+------------+---------------------+CODE_POINTS_TO_BYTES
CODE_POINTS_TO_BYTES(ascii_values)Description
Takes an array of extended ASCII code points (ARRAY of INT64) and returns BYTES.
To convert from BYTES to an array of code points, see TO_CODE_POINTS.
Return type
BYTES
Examples
The following is a basic example using CODE_POINTS_TO_BYTES.
SELECT CODE_POINTS_TO_BYTES([65, 98, 67, 100]) AS bytes;
+-------+
| bytes |
+-------+
| AbCd |
+-------+The following example uses a rotate-by-13 places (ROT13) algorithm to encode a string.
SELECT CODE_POINTS_TO_BYTES(ARRAY_AGG(
(SELECT
CASE
WHEN chr BETWEEN b'a' and b'z'
THEN TO_CODE_POINTS(b'a')[offset(0)] +
MOD(code+13-TO_CODE_POINTS(b'a')[offset(0)],26)
WHEN chr BETWEEN b'A' and b'Z'
THEN TO_CODE_POINTS(b'A')[offset(0)] +
MOD(code+13-TO_CODE_POINTS(b'A')[offset(0)],26)
ELSE code
END
FROM
(SELECT code, CODE_POINTS_TO_BYTES([code]) chr)
) ORDER BY OFFSET)) AS encoded_string
FROM UNNEST(TO_CODE_POINTS(b'Test String!')) code WITH OFFSET;
+----------------+
| encoded_string |
+----------------+
| Grfg Fgevat! |
+----------------+CODE_POINTS_TO_STRING
CODE_POINTS_TO_STRING(value)Description
Takes an array of Unicode code points (ARRAY of INT64) and returns a STRING.
To convert from a string to an array of code points, see TO_CODE_POINTS.
Return type
STRING
Example
The following is a basic example using CODE_POINTS_TO_STRING.
SELECT CODE_POINTS_TO_STRING([65, 255, 513, 1024]) AS string;
+--------+
| string |
+--------+
| AÿȁЀ |
+--------+The following example computes the frequency of letters in a set of words.
WITH Words AS (
SELECT word
FROM UNNEST(['foo', 'bar', 'baz', 'giraffe', 'llama']) AS word
)
SELECT
CODE_POINTS_TO_STRING([code_point]) AS letter,
COUNT(*) AS letter_count
FROM Words,
UNNEST(TO_CODE_POINTS(word)) AS code_point
GROUP BY 1
ORDER BY 2 DESC;
+--------+--------------+
| letter | letter_count |
+--------+--------------+
| a | 5 |
| f | 3 |
| r | 2 |
| b | 2 |
| l | 2 |
| o | 2 |
| g | 1 |
| z | 1 |
| e | 1 |
| m | 1 |
| i | 1 |
+--------+--------------+CONCAT
CONCAT(value1[, ...])Description
Concatenates one or more values into a single result.
Return type
STRING or BYTES
Examples
With Employees AS
(SELECT
"John" AS first_name,
"Doe" AS last_name
UNION ALL
SELECT
"Jane" AS first_name,
"Smith" AS last_name
UNION ALL
SELECT
"Joe" AS first_name,
"Jackson" AS last_name)
SELECT
CONCAT(first_name, " ", last_name)
AS full_name
FROM Employees;
+---------------------+
| full_name |
+---------------------+
| John Doe |
| Jane Smith |
| Joe Jackson |
+---------------------+ENDS_WITH
ENDS_WITH(value1, value2)Description
Takes two values. Returns TRUE if the second value is a suffix of the first.
Return type
BOOL
Examples
WITH items AS
(SELECT "apple" as item
UNION ALL
SELECT "banana" as item
UNION ALL
SELECT "orange" as item)
SELECT
ENDS_WITH(item, "e") as example
FROM items;
+---------+
| example |
+---------+
| True |
| False |
| True |
+---------+FORMAT
BigQuery supports a FORMAT() function for formatting strings. This
function is similar to the C printf function. It produces a
STRING from a format string that contains zero or
more format specifiers, along with a variable length list of additional
arguments that matches the format specifiers. Here are some examples:
| Description | Statement | Result |
|---|---|---|
| Simple integer | format("%d", 10) | 10 |
| Integer with left blank padding | format("|%10d|", 11) | | 11| |
| Integer with left zero padding | format("+%010d+", 12) | +0000000012+ |
| STRING | format("-%s-", 'abcd efg') | -abcd efg- |
| FLOAT64 | format("%f %E", 1.1, 2.2) | 1.100000 2.200000E+00 |
| DATE | format("%t", date "2015-09-01") | 2015-09-01 |
| TIMESTAMP | format("%t", timestamp "2015-09-01 12:34:56 America/Los_Angeles") | 2015‑09‑01 19:34:56+00 |
The FORMAT() function does not provide fully customizable formatting for all
types and values, nor formatting that is sensitive to locale.
If custom formatting is necessary for a type, you must first format it using
type-specific format functions, such as FORMAT_DATE() or FORMAT_TIMESTAMP().
For example:
FORMAT("date: %s!", FORMAT_DATE("%B %d, %Y", date '2015-01-02'));Returns
date: January 02, 2015!Syntax
The FORMAT() syntax takes a format string and variable length list of
arguments and produces a STRING result:
FORMAT(<format_string>, ...)The <format_string> expression can contain zero or more format specifiers.
Each format specifier is introduced by the % symbol, and must map to one or
more of the remaining arguments. For the most part, this is a one-to-one
mapping, except when the * specifier is present. For example, %.*i maps to
two arguments—a length argument and a signed integer argument. If the
number of arguments related to the format specifiers is not the same as the
number of arguments, an error occurs.
Supported format specifiers
The FORMAT() function format specifier follows this prototype:
%[flags][width][.precision]specifierThe supported format specifiers are identified in the following table. Extensions from printf() are identified in italics.
| Specifier | Description | Examples | Types |
d or i |
Decimal integer | 392 |
INT64 |
o |
Octal | 610 |
INT64* |
x |
Hexadecimal integer | 7fa |
INT64* |
X |
Hexadecimal integer (uppercase) | 7FA |
INT64* |
f |
Decimal floating point, lowercase | 392.65infNaN |
NUMERIC FLOAT64 |
F |
Decimal floating point, uppercase | 392.65infNAN |
NUMERIC FLOAT64 |
e |
Scientific notation (mantissa/exponent), lowercase | 3.9265e+2infNaN |
NUMERIC FLOAT64 |
E |
Scientific notation (mantissa/exponent), uppercase | 3.9265E+2infNAN |
NUMERIC FLOAT64 |
g |
Use the shortest representation, %e or %f | 392.65 |
FLOAT64 |
G |
Use the shortest representation, %E or %F | 392.65 |
FLOAT64 |
s |
String of characters | sample | STRING |
t |
Returns a printable string representing the value. Often looks similar to casting the argument to STRING. See %t section below. | sample 2014‑01‑01 |
<any> |
T |
Produces a string that is a valid BigQuery constant with a similar type to the value's type (maybe wider, or maybe string). See %T section below. | 'sample' b'bytes sample' 1234 2.3 date '2014‑01‑01' |
<any> |
% |
'%%' produces a single '%' | % | n/a |
*The specifiers o, x, and X raise an error if negative values are used.
The format specifier can optionally contain the sub-specifiers identified above in the specifier prototype.
These sub-specifiers must comply with the following specifications.
Flags
| Flags | Description |
- |
Left-justify within the given field width; Right justification is the default (see width sub-specifier) |
+ |
Forces to precede the result with a plus or minus sign (+
or -) even for positive numbers. By default, only negative numbers
are preceded with a - sign |
| <space> | If no sign is going to be written, a blank space is inserted before the value |
# |
Used with o, x or X specifiers. Precedes the value with 0, 0x or 0X respectively for values different than zero |
0 |
Left-pads the number with zeroes (0) instead of spaces when padding is specified (see width sub-specifier) |
' |
Formats integers using the appropriating grouping character. For example:
This flag is only relevant for decimal, hex, and octal values. |
Flags may be specified in any order. Duplicate flags are not an error. When flags are not relevant for some element type, they are ignored.
Width
| Width | Description |
| <number> | Minimum number of characters to be printed. If the value to be printed is shorter than this number, the result is padded with blank spaces. The value is not truncated even if the result is larger |
* |
The width is not specified in the format string, but as an additional integer value argument preceding the argument that has to be formatted |
Precision
| Precision | Description |
.<number> |
For integer specifiers (d, i, o, u, x, X): precision specifies the minimum number of digits to be written. If the value to be written is shorter than this number, the result is padded with trailing zeros. The value is not truncated even if the result is longer. A precision of 0 means that no character is written for the value 0. For a, A, e, E, f and F specifiers: this is the number of digits to be printed after the decimal point (by default, this is 6) |
.* |
The precision is not specified in the format string, but as an additional integer value argument preceding the argument that has to be formatted |
%t and %T behavior
The %t and %T format specifiers are defined for all types. The width,
precision, and flags act as they do for %s: the width is the minimum width
and the STRING will be padded to that size, and precision is the maximum width
of content to show and the STRING will be truncated to that size, prior to
padding to width.
%t is always meant to be a readable form of the value.
%T is always a valid SQL literal of a similar type, such as a wider numeric type. The literal will not include casts or a type name, except for the special case of non-finite floating point values.
The STRING is formatted as follows:
| Type | %t | %T |
NULL of any type |
NULL |
NULL |
| INT64 |
123 | 123 |
| NUMERIC | 123.0 (always with .0) | NUMERIC "123.0" |
| FLOAT64 | 123.0 (always with .0) 123e+10 inf-infNaN |
123.0 (always with .0) 123e+10 CAST("inf" AS <type>) CAST("-inf" AS <type>) CAST("nan" AS <type>) |
| STRING | unquoted string value | quoted string literal |
| BYTES | unquoted escaped bytes e.g. abc\x01\x02 |
quoted bytes literal e.g. b"abc\x01\x02" |
| DATE | 2011-02-03 | DATE "2011-02-03" |
| TIMESTAMP | 2011-02-03 04:05:06+00 | TIMESTAMP "2011-02-03 04:05:06+00" |
| ARRAY | [value, value, ...] where values are formatted with %t |
[value, value, ...] where values are formatted with %T |
| STRUCT | (value, value, ...) where fields are formatted with %t |
(value, value, ...) where fields are formatted with %T Special cases: Zero fields: STRUCT() One field: STRUCT(value) |
Error conditions
If a format specifier is invalid, or is not compatible with the related
argument type, or the wrong number or arguments are provided, then an error is
produced. For example, the following <format_string> expressions are invalid:
FORMAT('%s', 1)FORMAT('%')NULL argument handling
A NULL format string results in a NULL output STRING. Any other arguments are
ignored in this case.
The function generally produces a NULL value if a NULL argument is present. For
example, FORMAT('%i', <NULL expression>) produces a NULL
STRING as output.
However, there are some exceptions: if the format specifier is %t or %T (both of
which produce STRINGs that effectively match CAST and
literal value semantics), a NULL value produces 'NULL' (without the quotes) in
the result STRING. For example, the function:
FORMAT('00-%t-00', <NULL expression>);Returns
00-NULL-00Additional semantic rules
FLOAT64 values can be +/-inf or NaN. When an argument has one of
those values, the result of the format specifiers %f, %F, %e, %E, %g,
%G, and %t are inf, -inf, or nan (or the same in uppercase) as
appropriate. This is consistent with how BigQuery casts these values
to STRING. For %T, BigQuery returns quoted strings for
FLOAT64 values that don't have non-string literal
representations.
FROM_BASE32
FROM_BASE32(string_expr)Description
Converts the base32-encoded input string_expr into BYTES format. To convert
BYTES to a base32-encoded STRING, use TO_BASE32.
Return type
BYTES
Example
SELECT FROM_BASE32('MFRGGZDF74======') AS byte_data;
+-----------+
| byte_data |
+-----------+
| abcde\xff |
+-----------+FROM_BASE64
FROM_BASE64(string_expr)Description
Converts the base64-encoded input string_expr into BYTES format. To convert
BYTES to a base64-encoded STRING, use TO_BASE64.
Return type
BYTES
Example
SELECT FROM_BASE64('3q2+7w==') AS byte_data;
+------------------+
| byte_data |
+------------------+
| \xde\xad\xbe\xef |
+------------------+FROM_HEX
FROM_HEX(string)Description
Converts a hexadecimal-encoded STRING into BYTES format. Returns an error if the
input STRING contains characters outside the range
(0..9, A..F, a..f). The lettercase of the characters does not matter. To
convert BYTES to a hexadecimal-encoded
STRING, use TO_HEX.
Return type
BYTES
Example
WITH Input AS (
SELECT '00010203aaeeefff' AS hex_str UNION ALL
SELECT '0AF' UNION ALL
SELECT '666f6f626172'
)
SELECT hex_str, FROM_HEX(hex_str) AS bytes_str
FROM Input;
+------------------+----------------------------------+
| hex_str | bytes_str |
+------------------+----------------------------------+
| 0AF | \x00\xaf |
| 00010203aaeeefff | \x00\x01\x02\x03\xaa\xee\xef\xff |
| 666f6f626172 | foobar |
+------------------+----------------------------------+LENGTH
LENGTH(value)Description
Returns the length of the value. The returned value is in characters for STRING arguments and in bytes for the BYTES argument.
Return type
INT64
Examples
WITH example AS
(SELECT "абвгд" AS characters)
SELECT
characters,
LENGTH(characters) AS string_example,
LENGTH(CAST(characters AS BYTES)) AS bytes_example
FROM example;
+------------+----------------+---------------+
| characters | string_example | bytes_example |
+------------+----------------+---------------+
| абвгд | 5 | 10 |
+------------+----------------+---------------+LPAD
LPAD(original_value, return_length[, pattern])Description
Returns a value that consists of original_value prepended
with pattern. The return_length is an INT64 that specifies the length of the
returned value. If original_value is BYTES, return_length is the number of
bytes. If original_value is STRING, return_length is the number of
characters.
The default value of pattern is a blank space.
Both original_value and pattern must be the same data type.
If return_length is less than or equal to the original_value length, this
function returns the original_value value, truncated to the value of
return_length. For example, LPAD("hello world", 7); returns "hello w".
If original_value, return_length, or pattern is NULL, this function
returns NULL.
This function returns an error if:
return_lengthis negativepatternis empty
Return type
STRING or BYTES
Examples
SELECT t, len, FORMAT("%T", LPAD(t, len)) AS LPAD FROM UNNEST([
STRUCT('abc' AS t, 5 AS len),
('abc', 2),
('例子', 4)
]);| t | len | LPAD |
|---|---|---|
| abc | 5 | " abc" |
| abc | 2 | "ab" |
| 例子 | 4 | " 例子" |
SELECT t, len, pattern, FORMAT("%T", LPAD(t, len, pattern)) AS LPAD FROM UNNEST([
STRUCT('abc' AS t, 8 AS len, 'def' AS pattern),
('abc', 5, '-'),
('例子', 5, '中文')
]);| t | len | pattern | LPAD |
|---|---|---|---|
| abc | 8 | def | "defdeabc" |
| abc | 5 | - | "--abc" |
| 例子 | 5 | 中文 | "中文中例子" |
SELECT FORMAT("%T", t) AS t, len, FORMAT("%T", LPAD(t, len)) AS LPAD FROM UNNEST([
STRUCT(b'abc' AS t, 5 AS len),
(b'abc', 2),
(b'\xab\xcd\xef', 4)
]);| t | len | LPAD |
|---|---|---|
| b"abc" | 5 | b" abc" |
| b"abc" | 2 | b"ab" |
| b"\xab\xcd\xef" | 4 | b" \xab\xcd\xef" |
SELECT
FORMAT("%T", t) AS t,
len,
FORMAT("%T", pattern) AS pattern,
FORMAT("%T", LPAD(t, len, pattern)) AS LPAD
FROM UNNEST([
STRUCT(b'abc' AS t, 8 AS len, b'def' AS pattern),
(b'abc', 5, b'-'),
(b'\xab\xcd\xef', 5, b'\x00')
]);| t | len | pattern | LPAD |
|---|---|---|---|
| b"abc" | 8 | b"def" | b"defdeabc" |
| b"abc" | 5 | b"-" | b"--abc" |
| b"\xab\xcd\xef" | 5 | b"\x00" | b"\x00\x00\xab\xcd\xef" |
LOWER
LOWER(value)Description
For STRING arguments, returns the original string with all alphabetic characters in lowercase. Mapping between lowercase and uppercase is done according to the Unicode Character Database without taking into account language-specific mappings.
For BYTES arguments, the argument is treated as ASCII text, with all bytes greater than 127 left intact.
Return type
STRING or BYTES
Examples
WITH items AS
(SELECT
"FOO" as item
UNION ALL
SELECT
"BAR" as item
UNION ALL
SELECT
"BAZ" as item)
SELECT
LOWER(item) AS example
FROM items;
+---------+
| example |
+---------+
| foo |
| bar |
| baz |
+---------+LTRIM
LTRIM(value1[, value2])Description
Identical to TRIM, but only removes leading characters.
Return type
STRING or BYTES
Examples
WITH items AS
(SELECT " apple " as item
UNION ALL
SELECT " banana " as item
UNION ALL
SELECT " orange " as item)
SELECT
CONCAT("#", LTRIM(item), "#") as example
FROM items;
+-------------+
| example |
+-------------+
| #apple # |
| #banana # |
| #orange # |
+-------------+
WITH items AS
(SELECT "***apple***" as item
UNION ALL
SELECT "***banana***" as item
UNION ALL
SELECT "***orange***" as item)
SELECT
LTRIM(item, "*") as example
FROM items;
+-----------+
| example |
+-----------+
| apple*** |
| banana*** |
| orange*** |
+-----------+
WITH items AS
(SELECT "xxxapplexxx" as item
UNION ALL
SELECT "yyybananayyy" as item
UNION ALL
SELECT "zzzorangezzz" as item
UNION ALL
SELECT "xyzpearxyz" as item)
SELECT
LTRIM(item, "xyz") as example
FROM items;
+-----------+
| example |
+-----------+
| applexxx |
| bananayyy |
| orangezzz |
| pearxyz |
+-----------+NORMALIZE
NORMALIZE(value[, normalization_mode])Description
Takes a STRING, value, and returns it as a normalized string.
Normalization is used to ensure that two strings are equivalent. Normalization is often used in situations in which two strings render the same on the screen but have different Unicode code points.
NORMALIZE supports four optional normalization modes:
| Value | Name | Description |
|---|---|---|
| NFC | Normalization Form Canonical Composition | Decomposes and recomposes characters by canonical equivalence. |
| NFKC | Normalization Form Compatibility Composition | Decomposes characters by compatibility, then recomposes them by canonical equivalence. |
| NFD | Normalization Form Canonical Decomposition | Decomposes characters by canonical equivalence, and multiple combining characters are arranged in a specific order. |
| NFKD | Normalization Form Compatibility Decomposition | Decomposes characters by compatibility, and multiple combining characters are arranged in a specific order. |
The default normalization mode is NFC.
Return type
STRING
Examples
SELECT a, b, a = b as normalized
FROM (SELECT NORMALIZE('\u00ea') as a, NORMALIZE('\u0065\u0302') as b)
AS normalize_example;
+---+---+------------+
| a | b | normalized |
+---+---+------------+
| ê | ê | true |
+---+---+------------+The following example normalizes different space characters.
WITH EquivalentNames AS (
SELECT name
FROM UNNEST([
'Jane\u2004Doe',
'John\u2004Smith',
'Jane\u2005Doe',
'Jane\u2006Doe',
'John Smith']) AS name
)
SELECT
NORMALIZE(name, NFKC) AS normalized_name,
COUNT(*) AS name_count
FROM EquivalentNames
GROUP BY 1;
+-----------------+------------+
| normalized_name | name_count |
+-----------------+------------+
| John Smith | 2 |
| Jane Doe | 3 |
+-----------------+------------+NORMALIZE_AND_CASEFOLD
NORMALIZE_AND_CASEFOLD(value[, normalization_mode])Description
Takes a STRING, value, and performs the same actions as
NORMALIZE, as well as
casefolding for
case-insensitive operations.
NORMALIZE_AND_CASEFOLD supports four optional normalization modes:
| Value | Name | Description |
|---|---|---|
| NFC | Normalization Form Canonical Composition | Decomposes and recomposes characters by canonical equivalence. |
| NFKC | Normalization Form Compatibility Composition | Decomposes characters by compatibility, then recomposes them by canonical equivalence. |
| NFD | Normalization Form Canonical Decomposition | Decomposes characters by canonical equivalence, and multiple combining characters are arranged in a specific order. |
| NFKD | Normalization Form Compatibility Decomposition | Decomposes characters by compatibility, and multiple combining characters are arranged in a specific order. |
The default normalization mode is NFC.
Return type
STRING
Example
WITH Strings AS (
SELECT '\u2168' AS a, 'IX' AS b UNION ALL
SELECT '\u0041\u030A', '\u00C5'
)
SELECT a, b,
NORMALIZE_AND_CASEFOLD(a, NFD)=NORMALIZE_AND_CASEFOLD(b, NFD) AS nfd,
NORMALIZE_AND_CASEFOLD(a, NFC)=NORMALIZE_AND_CASEFOLD(b, NFC) AS nfc,
NORMALIZE_AND_CASEFOLD(a, NFKD)=NORMALIZE_AND_CASEFOLD(b, NFKD) AS nkfd,
NORMALIZE_AND_CASEFOLD(a, NFKC)=NORMALIZE_AND_CASEFOLD(b, NFKC) AS nkfc
FROM Strings;
+---+----+-------+-------+------+------+
| a | b | nfd | nfc | nkfd | nkfc |
+---+----+-------+-------+------+------+
| Ⅸ | IX | false | false | true | true |
| Å | Å | true | true | true | true |
+---+----+-------+-------+------+------+REGEXP_CONTAINS
REGEXP_CONTAINS(value, regex)Description
Returns TRUE if value is a partial match for the regular expression,
regex. You can search for a full match by using ^ (beginning of text) and
$ (end of text).
If the regex argument is invalid, the function returns an error.
Note: BigQuery provides regular expression support using the re2 library; see that documentation for its regular expression syntax.
Return type
BOOL
Examples
SELECT
email,
REGEXP_CONTAINS(email, r"@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+") AS is_valid
FROM
(SELECT
["foo@example.com", "bar@example.org", "www.example.net"]
AS addresses),
UNNEST(addresses) AS email;
+-----------------+----------+
| email | is_valid |
+-----------------+----------+
| foo@example.com | true |
| bar@example.org | true |
| www.example.net | false |
+-----------------+----------+
# Performs a full match, using ^ and $.
SELECT
email,
REGEXP_CONTAINS(email, r"^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$")
AS valid_email_address
FROM
(SELECT
["foo@example.com", "bar@example.org", "www.example.net"]
AS addresses),
UNNEST(addresses) AS email;
+-----------------+---------------------+
| email | valid_email_address |
+-----------------+---------------------+
| foo@example.com | true |
| bar@example.org | true |
| www.example.net | false |
+-----------------+---------------------+REGEXP_EXTRACT
REGEXP_EXTRACT(value, regex)Description
Returns the first substring in value that matches the regular expression,
regex. Returns NULL if there is no match.
If the regular expression contains a capturing group, the function returns the substring that is matched by that capturing group. If the expression does not contain a capturing group, the function returns the entire matching substring.
Returns an error if:
- The regular expression is invalid
- The regular expression has more than one capturing group
Note: BigQuery provides regular expression support using the re2 library; see that documentation for its regular expression syntax.
Return type
STRING or BYTES
Examples
WITH email_addresses AS
(SELECT "foo@example.com" as email
UNION ALL
SELECT "bar@example.org" as email
UNION ALL
SELECT "baz@example.net" as email)
SELECT
REGEXP_EXTRACT(email, r"^[a-zA-Z0-9_.+-]+")
AS user_name
FROM email_addresses;
+-----------+
| user_name |
+-----------+
| foo |
| bar |
| baz |
+-----------+
WITH email_addresses AS
(SELECT "foo@example.com" as email
UNION ALL
SELECT "bar@example.org" as email
UNION ALL
SELECT "baz@example.net" as email)
SELECT
REGEXP_EXTRACT(email, r"^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.([a-zA-Z0-9-.]+$)")
AS top_level_domain
FROM email_addresses;
+------------------+
| top_level_domain |
+------------------+
| com |
| org |
| net |
+------------------+REGEXP_EXTRACT_ALL
REGEXP_EXTRACT_ALL(value, regex)Description
Returns an array of all substrings of value that match the regular expression,
regex.
The REGEXP_EXTRACT_ALL function only returns non-overlapping matches. For
example, using this function to extract ana from banana returns only one
substring, not two.
Note: BigQuery provides regular expression support using the re2 library; see that documentation for its regular expression syntax.
Return type
An ARRAY of either STRINGs or BYTES
Examples
WITH code_markdown AS
(SELECT "Try `function(x)` or `function(y)`" as code)
SELECT
REGEXP_EXTRACT_ALL(code, "`(.+?)`") AS example
FROM code_markdown;
+----------------------------+
| example |
+----------------------------+
| [function(x), function(y)] |
+----------------------------+REGEXP_REPLACE
REGEXP_REPLACE(value, regex, replacement)Description
Returns a STRING where all substrings of value that
match regular expression regex are replaced with replacement.
You can use backslashed-escaped digits (\1 to \9) within the replacement
argument to insert text matching the corresponding parenthesized group in the
regex pattern. Use \0 to refer to the entire matching text.
Note: To add a backslash in your regular expression, you must first escape it.
For example, SELECT REGEXP_REPLACE("abc", "b(.)", "X\\1"); returns aXc.
The REGEXP_REPLACE function only replaces non-overlapping matches. For
example, replacing ana within banana results in only one replacement, not
two.
If the regex argument is not a valid regular expression, this function returns
an error.
Note: BigQuery provides regular expression support using the re2 library; see that documentation for its regular expression syntax.
Return type
STRING or BYTES
Examples
WITH markdown AS
(SELECT "# Heading" as heading
UNION ALL
SELECT "# Another heading" as heading)
SELECT
REGEXP_REPLACE(heading, r"^# ([a-zA-Z0-9\s]+$)", "<h1>\\1</h1>")
AS html
FROM markdown;
+--------------------------+
| html |
+--------------------------+
| <h1>Heading</h1> |
| <h1>Another heading</h1> |
+--------------------------+REPLACE
REPLACE(original_value, from_value, to_value)Description
Replaces all occurrences of from_value with to_value in original_value.
If from_value is empty, no replacement is made.
Return type
STRING or BYTES
Examples
WITH desserts AS
(SELECT "apple pie" as dessert
UNION ALL
SELECT "blackberry pie" as dessert
UNION ALL
SELECT "cherry pie" as dessert)
SELECT
REPLACE (dessert, "pie", "cobbler") as example
FROM desserts;
+--------------------+
| example |
+--------------------+
| apple cobbler |
| blackberry cobbler |
| cherry cobbler |
+--------------------+REPEAT
REPEAT(original_value, repetitions)Description
Returns a value that consists of original_value, repeated.
The repetitions parameter specifies the number of times to repeat
original_value. Returns NULL if either original_value or repetitions are
NULL.
This function return an error if the repetitions value is negative.
Return type
STRING or BYTES
Examples
SELECT t, n, REPEAT(t, n) AS REPEAT FROM UNNEST([
STRUCT('abc' AS t, 3 AS n),
('例子', 2),
('abc', null),
(null, 3)
]);| t | n | REPEAT |
|---|---|---|
| abc | 3 | abcabcabc |
| 例子 | 2 | 例子例子 |
| abc | NULL | NULL |
| NULL | 3 | NULL |
REVERSE
REVERSE(value)Description
Returns the reverse of the input STRING or BYTES.
Return type
STRING or BYTES
Examples
WITH example AS (
SELECT "foo" AS sample_string, b"bar" AS sample_bytes UNION ALL
SELECT "абвгд" AS sample_string, b"123" AS sample_bytes
)
SELECT
sample_string,
REVERSE(sample_string) AS reverse_string,
sample_bytes,
REVERSE(sample_bytes) AS reverse_bytes
FROM example;
+---------------+----------------+--------------+---------------+
| sample_string | reverse_string | sample_bytes | reverse_bytes |
+---------------+----------------+--------------+---------------+
| foo | oof | bar | rab |
| абвгд | дгвба | 123 | 321 |
+---------------+----------------+--------------+---------------+RPAD
RPAD(original_value, return_length[, pattern])Description
Returns a value that consists of original_value appended
with pattern. The return_length is an INT64 that specifies the length of the
returned value. If original_value is BYTES, return_length is the number of
bytes. If original_value is STRING, return_length is the number of
characters.
The default value of pattern is a blank space.
Both original_value and pattern must be the same data type.
If return_length is less than or equal to the original_value length, this
function returns the original_value value, truncated to the value of
return_length. For example, RPAD("hello world", 7); returns "hello w".
If original_value, return_length, or pattern is NULL, this function
returns NULL.
This function returns an error if:
return_lengthis negativepatternis empty
Return type
STRING or BYTES
Examples
SELECT t, len, FORMAT("%T", RPAD(t, len)) AS RPAD FROM UNNEST([
STRUCT('abc' AS t, 5 AS len),
('abc', 2),
('例子', 4)
]);| t | len | RPAD |
|---|---|---|
| abc | 5 | "abc " |
| abc | 2 | "ab" |
| 例子 | 4 | "例子 " |
SELECT t, len, pattern, FORMAT("%T", RPAD(t, len, pattern)) AS RPAD FROM UNNEST([
STRUCT('abc' AS t, 8 AS len, 'def' AS pattern),
('abc', 5, '-'),
('例子', 5, '中文')
]);| t | len | pattern | RPAD |
|---|---|---|---|
| abc | 8 | def | "abcdefde" |
| abc | 5 | - | "abc--" |
| 例子 | 5 | 中文 | "例子中文中" |
SELECT FORMAT("%T", t) AS t, len, FORMAT("%T", RPAD(t, len)) AS RPAD FROM UNNEST([
STRUCT(b'abc' AS t, 5 AS len),
(b'abc', 2),
(b'\xab\xcd\xef', 4)
]);| t | len | RPAD |
|---|---|---|
| b"abc" | 5 | b"abc " |
| b"abc" | 2 | b"ab" |
| b"\xab\xcd\xef" | 4 | b"\xab\xcd\xef " |
SELECT
FORMAT("%T", t) AS t,
len,
FORMAT("%T", pattern) AS pattern,
FORMAT("%T", RPAD(t, len, pattern)) AS RPAD
FROM UNNEST([
STRUCT(b'abc' AS t, 8 AS len, b'def' AS pattern),
(b'abc', 5, b'-'),
(b'\xab\xcd\xef', 5, b'\x00')
]);| t | len | pattern | RPAD |
|---|---|---|---|
| b"abc" | 8 | b"def" | b"abcdefde" |
| b"abc" | 5 | b"-" | b"abc--" |
| b"\xab\xcd\xef" | 5 | b"\x00" | b"\xab\xcd\xef\x00\x00" |
RTRIM
RTRIM(value1[, value2])Description
Identical to TRIM, but only removes trailing characters.
Return type
STRING or BYTES
Examples
WITH items AS
(SELECT "***apple***" as item
UNION ALL
SELECT "***banana***" as item
UNION ALL
SELECT "***orange***" as item)
SELECT
RTRIM(item, "*") as example
FROM items;
+-----------+
| example |
+-----------+
| ***apple |
| ***banana |
| ***orange |
+-----------+
WITH items AS
(SELECT "applexxx" as item
UNION ALL
SELECT "bananayyy" as item
UNION ALL
SELECT "orangezzz" as item
UNION ALL
SELECT "pearxyz" as item)
SELECT
RTRIM(item, "xyz") as example
FROM items;
+---------+
| example |
+---------+
| apple |
| banana |
| orange |
| pear |
+---------+SAFE_CONVERT_BYTES_TO_STRING
SAFE_CONVERT_BYTES_TO_STRING(value)Description
Converts a sequence of bytes to a string. Any invalid UTF-8 characters are
replaced with the Unicode replacement character, U+FFFD.
Return type
STRING
Examples
The following statement returns the Unicode replacement character, �.
SELECT SAFE_CONVERT_BYTES_TO_STRING(b'\xc2') as safe_convert;SPLIT
SPLIT(value[, delimiter])Description
Splits value using the delimiter argument.
For STRING, the default delimiter is the comma ,.
For BYTES, you must specify a delimiter.
Splitting on an empty delimiter produces an array of UTF-8 characters for STRING values, and an array of BYTES for BYTES values.
Splitting an empty STRING returns an ARRAY with a single empty STRING.
Return type
ARRAY of type STRING or ARRAY of type BYTES
Examples
WITH letters AS
(SELECT "a b c d" as letter_group
UNION ALL
SELECT "e f g h" as letter_group
UNION ALL
SELECT "i j k l" as letter_group)
SELECT SPLIT(letter_group, " ") as example
FROM letters;
+----------------------+
| example |
+----------------------+
| [a, b, c, d] |
| [e, f, g, h] |
| [i, j, k, l] |
+----------------------+STARTS_WITH
STARTS_WITH(value1, value2)Description
Takes two values. Returns TRUE if the second value is a prefix of the first.
Return type
BOOL
Examples
WITH items AS
(SELECT "foo" as item
UNION ALL
SELECT "bar" as item
UNION ALL
SELECT "baz" as item)
SELECT
STARTS_WITH(item, "b") as example
FROM items;
+---------+
| example |
+---------+
| False |
| True |
| True |
+---------+STRPOS
STRPOS(string, substring)Description
Returns the 1-based index of the first occurrence of substring inside
string. Returns 0 if substring is not found.
Return type
INT64
Examples
WITH email_addresses AS
(SELECT
"foo@example.com" AS email_address
UNION ALL
SELECT
"foobar@example.com" AS email_address
UNION ALL
SELECT
"foobarbaz@example.com" AS email_address
UNION ALL
SELECT
"quxexample.com" AS email_address)
SELECT
STRPOS(email_address, "@") AS example
FROM email_addresses;
+---------+
| example |
+---------+
| 4 |
| 7 |
| 10 |
| 0 |
+---------+SUBSTR
SUBSTR(value, position[, length])Description
Returns a substring of the supplied value. The position
argument is an integer specifying the starting position of the substring, with
position = 1 indicating the first character or byte. The length
argument is the maximum number of characters for
STRING arguments, or bytes for
BYTES arguments.
If position is negative, the function counts from the end of value,
with -1 indicating the last character.
If position is a position off the left end of the
STRING (position = 0 or
position < -LENGTH(value)), the function starts
from position = 1. If length exceeds the length of
value, returns fewer than length characters.
If length is less than 0, the function returns an error.
Return type
STRING or BYTES
Examples
WITH items AS
(SELECT "apple" as item
UNION ALL
SELECT "banana" as item
UNION ALL
SELECT "orange" as item)
SELECT
SUBSTR(item, 2) as example
FROM items;
+---------+
| example |
+---------+
| pple |
| anana |
| range |
+---------+
WITH items AS
(SELECT "apple" as item
UNION ALL
SELECT "banana" as item
UNION ALL
SELECT "orange" as item)
SELECT
SUBSTR(item, 2, 2) as example
FROM items;
+---------+
| example |
+---------+
| pp |
| an |
| ra |
+---------+
WITH items AS
(SELECT "apple" as item
UNION ALL
SELECT "banana" as item
UNION ALL
SELECT "orange" as item)
SELECT
SUBSTR(item, -2) as example
FROM items;
+---------+
| example |
+---------+
| le |
| na |
| ge |
+---------+TO_BASE32
TO_BASE32(bytes_expr)Description
Converts a sequence of BYTES into a base32-encoded STRING. To convert a base32-encoded STRING into BYTES, use FROM_BASE32.
Return type
STRING
Example
SELECT TO_BASE32(b'abcde\xFF') AS base32_string;
+------------------+
| base32_string |
+------------------+
| MFRGGZDF74====== |
+------------------+TO_BASE64
TO_BASE64(bytes_expr)Description
Converts a sequence of BYTES into a base64-encoded STRING. To convert a base64-encoded STRING into BYTES, use FROM_BASE64.
Return type
STRING
Example
SELECT TO_BASE64(b'\xde\xad\xbe\xef') AS base64_string;
+---------------+
| base64_string |
+---------------+
| 3q2+7w== |
+---------------+TO_CODE_POINTS
TO_CODE_POINTS(value)Description
Takes a value and returns an array of INT64.
- If
valueis a STRING, each element in the returned array represents a code point. Each code point falls within the range of [0, 0xD7FF] and [0xE000, 0x10FFFF]. - If
valueis BYTES, each element in the array is an extended ASCII character value in the range of [0, 255].
To convert from an array of code points to a STRING or BYTES, see CODE_POINTS_TO_STRING or CODE_POINTS_TO_BYTES.
Return type
ARRAY of INT64
Examples
The following example gets the code points for each element in an array of words.
SELECT word, TO_CODE_POINTS(word) AS code_points
FROM UNNEST(['foo', 'bar', 'baz', 'giraffe', 'llama']) AS word;
+---------+------------------------------------+
| word | code_points |
+---------+------------------------------------+
| foo | [102, 111, 111] |
| bar | [98, 97, 114] |
| baz | [98, 97, 122] |
| giraffe | [103, 105, 114, 97, 102, 102, 101] |
| llama | [108, 108, 97, 109, 97] |
+---------+------------------------------------+The following example converts integer representations of BYTES to their corresponding ASCII character values.
SELECT word, TO_CODE_POINTS(word) AS bytes_value_as_integer
FROM UNNEST([b'\x00\x01\x10\xff', b'\x66\x6f\x6f']) AS word;
+------------------+------------------------+
| word | bytes_value_as_integer |
+------------------+------------------------+
| \x00\x01\x10\xff | [0, 1, 16, 255] |
| foo | [102, 111, 111] |
+------------------+------------------------+The following example demonstrates the difference between a BYTES result and a STRING result.
SELECT TO_CODE_POINTS(b'Ā') AS b_result, TO_CODE_POINTS('Ā') AS s_result;
+------------+----------+
| b_result | s_result |
+------------+----------+
| [196, 128] | [256] |
+------------+----------+Notice that the character, Ā, is represented as a two-byte Unicode sequence. As
a result, the BYTES version of TO_CODE_POINTS returns an array with two
elements, while the STRING version returns an array with a single element.
TO_HEX
TO_HEX(bytes)Description
Converts a sequence of BYTES into a hexadecimal
STRING. Converts each byte in
the STRING as two hexadecimal characters in the range
(0..9, a..f). To convert a hexadecimal-encoded
STRING
to BYTES, use FROM_HEX.
Return type
STRING
Example
WITH Input AS (
SELECT b'\x00\x01\x02\x03\xAA\xEE\xEF\xFF' AS byte_str UNION ALL
SELECT b'foobar'
)
SELECT byte_str, TO_HEX(byte_str) AS hex_str
FROM Input;
+----------------------------------+------------------+
| byte_string | hex_string |
+----------------------------------+------------------+
| foobar | 666f6f626172 |
| \x00\x01\x02\x03\xaa\xee\xef\xff | 00010203aaeeefff |
+----------------------------------+------------------+TRIM
TRIM(value1[, value2])Description
Removes all leading and trailing characters that match value2. If
value2 is not specified, all leading and trailing whitespace characters (as
defined by the Unicode standard) are removed. If the first argument is of type
BYTES, the second argument is required.
If value2 contains more than one character or byte, the function removes all
leading or trailing characters or bytes contained in value2.
Return type
STRING or BYTES
Examples
WITH items AS
(SELECT " apple " as item
UNION ALL
SELECT " banana " as item
UNION ALL
SELECT " orange " as item)
SELECT
CONCAT("#", TRIM(item), "#") as example
FROM items;
+----------+
| example |
+----------+
| #apple# |
| #banana# |
| #orange# |
+----------+
WITH items AS
(SELECT "***apple***" as item
UNION ALL
SELECT "***banana***" as item
UNION ALL
SELECT "***orange***" as item)
SELECT
TRIM(item, "*") as example
FROM items;
+---------+
| example |
+---------+
| apple |
| banana |
| orange |
+---------+
WITH items AS
(SELECT "xxxapplexxx" as item
UNION ALL
SELECT "yyybananayyy" as item
UNION ALL
SELECT "zzzorangezzz" as item
UNION ALL
SELECT "xyzpearxyz" as item)
SELECT
TRIM(item, "xyz") as example
FROM items;
+---------+
| example |
+---------+
| apple |
| banana |
| orange |
| pear |
+---------+UPPER
UPPER(value)Description
For STRING arguments, returns the original string with all alphabetic characters in uppercase. Mapping between uppercase and lowercase is done according to the Unicode Character Database without taking into account language-specific mappings.
For BYTES arguments, the argument is treated as ASCII text, with all bytes greater than 127 left intact.
Return type
STRING or BYTES
Examples
WITH items AS
(SELECT
"foo" as item
UNION ALL
SELECT
"bar" as item
UNION ALL
SELECT
"baz" as item)
SELECT
UPPER(item) AS example
FROM items;
+---------+
| example |
+---------+
| FOO |
| BAR |
| BAZ |
+---------+JSON functions
BigQuery supports functions that help you retrieve data stored in JSON-formatted strings and functions that help you transform data into JSON-formatted strings.
JSON_EXTRACT or JSON_EXTRACT_SCALAR
JSON_EXTRACT(json_string_expr,
json_path_string_literal), which returns JSON values as STRINGs.
JSON_EXTRACT_SCALAR(json_string_expr,
json_path_string_literal), which returns scalar JSON values as STRINGs.
Description
The json_string_expr parameter must be a JSON-formatted string. For example:
{"class" : {"students" : [{"name" : "Jane"}]}}The json_path_string_literal parameter identifies the value or values you want
to obtain from the JSON-formatted string. You construct this parameter using the
JSONPath format. As part of this format,
this parameter must start with a $ symbol, which refers to the outermost level
of the JSON-formatted string. You can identify child values using dot or
bracket notation. If the JSON object is an array, you can use brackets to
specify the array index.
| JSONPath | Description |
|---|---|
| $ | Root object or element |
| . or [] | Child operator |
| [] | Subscript operator |
Both functions return NULL if the json_path_string_literal parameter does
not match a value in json_string_expr. If the selected value for
JSON_EXTRACT_SCALAR is not scalar, such as an object or an array, the function
returns NULL.
If the JSONPath is invalid, these functions raise an error.
In cases where a JSON key uses invalid JSONPath characters, you can escape those
characters using single quotes and brackets, [' ']. For example:
SELECT JSON_EXTRACT_SCALAR('{"a.b": {"c": "world"}}', "$['a.b'].c") as hello;
+-------+
| hello |
+-------+
| world |
+-------+Examples
SELECT JSON_EXTRACT(json_text, '$') AS json_text_string
FROM UNNEST([
'{"class" : {"students" : [{"name" : "Jane"}]}}',
'{"class" : {"students" : []}}',
'{"class" : {"students" : [{"name" : "John"}, {"name": "Jamie"}]}}'
]) AS json_text;The above query produces the following result:
+-----------------------------------------------------------+
| json_text_string |
+-----------------------------------------------------------+
| {"class":{"students":[{"name":"Jane"}]}} |
| {"class":{"students":[]}} |
| {"class":{"students":[{"name":"John"},{"name":"Jamie"}]}} |
+-----------------------------------------------------------+SELECT JSON_EXTRACT(json_text, '$.class.students[0]') AS first_student
FROM UNNEST([
'{"class" : {"students" : [{"name" : "Jane"}]}}',
'{"class" : {"students" : []}}',
'{"class" : {"students" : [{"name" : "John"}, {"name": "Jamie"}]}}'
]) AS json_text;The above query produces the following result:
+-----------------+
| first_student |
+-----------------+
| {"name":"Jane"} |
| NULL |
| {"name":"John"} |
+-----------------+SELECT JSON_EXTRACT(json_text, '$.class.students[1].name') AS second_student_name
FROM UNNEST([
'{"class" : {"students" : [{"name" : "Jane"}]}}',
'{"class" : {"students" : []}}',
'{"class" : {"students" : [{"name" : "John"}, {"name": "Jamie"}]}}'
]) AS json_text;The above query produces the following result:
+-------------------+
| second_student |
+-------------------+
| NULL |
| NULL |
| {"first":"Jamie"} |
+-------------------+SELECT JSON_EXTRACT(json_text, "$.class['students']") AS student_names
FROM UNNEST([
'{"class" : {"students" : [{"name" : "Jane"}]}}',
'{"class" : {"students" : []}}',
'{"class" : {"students" : [{"name" : "John"}, {"name": "Jamie"}]}}'
]) AS json_text;The above query produces the following result:
+------------------------------------+
| student_names |
+------------------------------------+
| [{"name":"Jane"}] |
| [] |
| [{"name":"John"},{"name":"Jamie"}] |
+------------------------------------+SELECT JSON_EXTRACT('{ "name" : "Jakob", "age" : "6" }', '$.name') as json_name,
JSON_EXTRACT_SCALAR('{ "name" : "Jakob", "age" : "6" }', '$.name') as scalar_name,
JSON_EXTRACT('{ "name" : "Jakob", "age" : "6" }', '$.age') as json_age,
JSON_EXTRACT_SCALAR('{ "name" : "Jakob", "age" : "6" }', '$.age') as scalar;The above query produces the following result:
+-----------+-------------+----------+--------+
| json_name | scalar_name | json_age | scalar |
+-----------+-------------+----------+--------+
| "Jakob" | Jakob | "6" | 6 |
+-----------+-------------+----------+--------+TO_JSON_STRING
TO_JSON_STRING(value[, pretty_print])Description
Returns a JSON-formatted string representation of value. This function
supports an optional pretty_print parameter. If pretty_print is present, the
returned value is formatted for easy readability.
| Input data type | Returned value |
|---|---|
| NULL of any type | null |
| BOOL | true or false. |
| INT64 | Same as -10123456789019007199254740992-9007199254740992"9007199254740993"
|
| NUMERIC | Same as -10"9007199254740993""123.56"
|
| FLOAT64 | +/-inf and NaN are represented as
Infinity, -Infinity, and NaN,
respectively.
Otherwise, the same as |
| STRING | Quoted string value, escaped according to the JSON standard.
Specifically, ", \, and the control characters
from U+0000 to U+001F are escaped. |
| BYTES | Quoted RFC 4648 base64-escaped value. For example:
|
| DATE | Quoted date. For example: "2017-03-06"
|
| TIMESTAMP | Quoted ISO 8601 date-time, where T separates the date and time and Zulu/UTC represents the time zone. For example: "2017-03-06T12:34:56.789012Z"
|
| DATETIME | Quoted ISO 8601 date-time, where T separates the date and time. For example: "2017-03-06T12:34:56.789012"
|
| TIME | Quoted ISO 8601 time. For example: "12:34:56.789012" |
| ARRAY |
[ elem1, elem2, ... ] Where each elem is formatted according to the element type. The empty
array is represented as |
| STRUCT | {"field_name1":field_value1,"field_name2":field_value2,...}
Where each {
"field_name1": field_value1,
"field_name2": field_value2,
...
}
Where each Fields with duplicate names might result in unparseable JSON. Anonymous
fields are represented with Invalid UTF-8 field names might result in unparseable JSON. String values
are escaped according to the JSON standard. Specifically, |
Return type
JSON string representation of the value.
Examples
Convert rows in a table to JSON.
WITH Input AS (
SELECT [1, 2] AS x, 'foo' AS y, STRUCT(true AS a, DATE '2017-04-05' AS b) AS s UNION ALL
SELECT NULL AS x, '' AS y, STRUCT(false AS a, DATE '0001-01-01' AS b) AS s UNION ALL
SELECT [3] AS x, 'bar' AS y, STRUCT(NULL AS a, DATE '2016-12-05' AS b) AS s
)
SELECT
t,
TO_JSON_STRING(t) AS json_row
FROM Input AS t;The above query produces the following result:
+-----------------------------------+-------------------------------------------------------+
| t | json_row |
+-----------------------------------+-------------------------------------------------------+
| {[1, 2], foo, {true, 2017-04-05}} | {"x":[1,2],"y":"foo","s":{"a":true,"b":"2017-04-05"}} |
| {NULL, , {false, 0001-01-01}} | {"x":null,"y":"","s":{"a":false,"b":"0001-01-01"}} |
| {[3], bar, {NULL, 2016-12-05}} | {"x":[3],"y":"bar","s":{"a":null,"b":"2016-12-05"}} |
+-----------------------------------+-------------------------------------------------------+Convert rows in a table to JSON with formatting.
WITH Input AS (
SELECT [1, 2] AS x, 'foo' AS y, STRUCT(true AS a, DATE '2017-04-05' AS b) AS s UNION ALL
SELECT NULL AS x, '' AS y, STRUCT(false AS a, DATE '0001-01-01' AS b) AS s UNION ALL
SELECT [3] AS x, 'bar' AS y, STRUCT(NULL AS a, DATE '2016-12-05' AS b) AS s
)
SELECT
TO_JSON_STRING(t, true) AS json_row
FROM Input AS t;The above query produces the following result:
+-----------------------+
| json_row |
+-----------------------+
| { |
| "x": [ |
| 1, |
| 2 |
| ], |
| "y": "foo", |
| "s": { |
| "a": true, |
| "b": "2017-04-05" |
| } |
|} |
| { |
| "x": null, |
| "y": "", |
| "s": { |
| "a": false, |
| "b": "0001-01-01" |
| } |
|} |
| { |
| "x": [ |
| 3 |
| ], |
| "y": "bar", |
| "s": { |
| "a": null, |
| "b": "2016-12-05" |
| } |
|} |
+-----------------------+Array functions
ARRAY
ARRAY(subquery)Description
The ARRAY function returns an ARRAY with one element for each row in a
subquery.
If subquery produces a
standard SQL table,
the table must have exactly one column. Each element in the output ARRAY is
the value of the single column of a row in the table.
If subquery produces a
value table, then
each element in the output ARRAY is the entire corresponding row of the value
table.
Constraints
- Subqueries are unordered, so the elements of the output
ARRAYare not guaranteed to preserve any order in the source table for the subquery. However, if the subquery includes anORDER BYclause, theARRAYfunction will return anARRAYthat honors that clause. - If the subquery returns more than one column, the
ARRAYfunction returns an error. - If the subquery returns an
ARRAYtyped column orARRAYtyped rows, theARRAYfunction returns an error: BigQuery does not supportARRAYs with elements of typeARRAY. - If the subquery returns zero rows, the
ARRAYfunction returns an emptyARRAY. It never returns aNULLARRAY.
Return type
ARRAY
Examples
SELECT ARRAY
(SELECT 1 UNION ALL
SELECT 2 UNION ALL
SELECT 3) AS new_array;
+-----------+
| new_array |
+-----------+
| [1, 2, 3] |
+-----------+To construct an ARRAY from a subquery that contains multiple
columns, change the subquery to use SELECT AS STRUCT. Now
the ARRAY function will return an ARRAY of STRUCTs. The ARRAY will
contain one STRUCT for each row in the subquery, and each of these STRUCTs
will contain a field for each column in that row.
SELECT
ARRAY
(SELECT AS STRUCT 1, 2, 3
UNION ALL SELECT AS STRUCT 4, 5, 6) AS new_array;
+------------------------+
| new_array |
+------------------------+
| [{1, 2, 3}, {4, 5, 6}] |
+------------------------+Similarly, to construct an ARRAY from a subquery that contains
one or more ARRAYs, change the subquery to use SELECT AS STRUCT.
SELECT ARRAY
(SELECT AS STRUCT [1, 2, 3] UNION ALL
SELECT AS STRUCT [4, 5, 6]) AS new_array;
+----------------------------+
| new_array |
+----------------------------+
| [{[1, 2, 3]}, {[4, 5, 6]}] |
+----------------------------+ARRAY_CONCAT
ARRAY_CONCAT(array_expression_1 [, array_expression_n])Description
Concatenates one or more arrays with the same element type into a single array.
Return type
ARRAY
Examples
SELECT ARRAY_CONCAT([1, 2], [3, 4], [5, 6]) as count_to_six;
+--------------------------------------------------+
| count_to_six |
+--------------------------------------------------+
| [1, 2, 3, 4, 5, 6] |
+--------------------------------------------------+ARRAY_LENGTH
ARRAY_LENGTH(array_expression)Description
Returns the size of the array. Returns 0 for an empty array. Returns NULL if
the array_expression is NULL.
Return type
INT64
Examples
WITH items AS
(SELECT ["apples", "bananas", NULL, "grapes"] as list
UNION ALL
SELECT ["coffee", "tea", "milk" ] as list
UNION ALL
SELECT ["cake", "pie"] as list)
SELECT list, ARRAY_LENGTH(list) AS size
FROM items
ORDER BY size DESC;
+---------------------------------+------+
| list | size |
+---------------------------------+------+
| [apples, bananas, NULL, grapes] | 4 |
| [coffee, tea, milk] | 3 |
| [cake, pie] | 2 |
+---------------------------------+------+ARRAY_TO_STRING
ARRAY_TO_STRING(array_expression, delimiter[, null_text])Description
Returns a concatenation of the elements in array_expression
as a STRING. The value for array_expression
can either be an array of STRING or
BYTES data types.
If the null_text parameter is used, the function replaces any NULL values in
the array with the value of null_text.
If the null_text parameter is not used, the function omits the NULL value
and its preceding delimiter.
Examples
WITH items AS
(SELECT ["apples", "bananas", "pears", "grapes"] as list
UNION ALL
SELECT ["coffee", "tea", "milk" ] as list
UNION ALL
SELECT ["cake", "pie", NULL] as list)
SELECT ARRAY_TO_STRING(list, '--') AS text
FROM items;
+--------------------------------+
| text |
+--------------------------------+
| apples--bananas--pears--grapes |
| coffee--tea--milk |
| cake--pie |
+--------------------------------+
WITH items AS
(SELECT ["apples", "bananas", "pears", "grapes"] as list
UNION ALL
SELECT ["coffee", "tea", "milk" ] as list
UNION ALL
SELECT ["cake", "pie", NULL] as list)
SELECT ARRAY_TO_STRING(list, '--', 'MISSING') AS text
FROM items;
+--------------------------------+
| text |
+--------------------------------+
| apples--bananas--pears--grapes |
| coffee--tea--milk |
| cake--pie--MISSING |
+--------------------------------+GENERATE_ARRAY
GENERATE_ARRAY(start_expression, end_expression[, step_expression])Description
Returns an array of values. The start_expression and end_expression
parameters determine the inclusive start and end of the array.
The GENERATE_ARRAY function accepts the following data types as inputs:
- INT64
- NUMERIC
- FLOAT64
The step_expression parameter determines the increment used to
generate array values. The default value for this parameter is 1.
This function returns an error if step_expression is set to 0, or if any
input is NaN.
If any argument is NULL, the function will return a NULL array.
Return Data Type
ARRAY
Examples
The following returns an array of integers, with a default step of 1.
SELECT GENERATE_ARRAY(1, 5) AS example_array;
+-----------------+
| example_array |
+-----------------+
| [1, 2, 3, 4, 5] |
+-----------------+The following returns an array using a user-specified step size.
SELECT GENERATE_ARRAY(0, 10, 3) AS example_array;
+---------------+
| example_array |
+---------------+
| [0, 3, 6, 9] |
+---------------+The following returns an array using a negative value, -3 for its step size.
SELECT GENERATE_ARRAY(10, 0, -3) AS example_array;
+---------------+
| example_array |
+---------------+
| [10, 7, 4, 1] |
+---------------+The following returns an array using the same value for the start_expression
and end_expression.
SELECT GENERATE_ARRAY(4, 4, 10) AS example_array;
+---------------+
| example_array |
+---------------+
| [4] |
+---------------+The following returns an empty array, because the start_expression is greater
than the end_expression, and the step_expression value is positive.
SELECT GENERATE_ARRAY(10, 0, 3) AS example_array;
+---------------+
| example_array |
+---------------+
| [] |
+---------------+The following returns a NULL array because end_expression is NULL.
SELECT GENERATE_ARRAY(5, NULL, 1) AS example_array;
+---------------+
| example_array |
+---------------+
| NULL |
+---------------+The following returns multiple arrays.
SELECT GENERATE_ARRAY(start, 5) AS example_array
FROM UNNEST([3, 4, 5]) AS start;
+---------------+
| example_array |
+---------------+
| [3, 4, 5] |
| [4, 5] |
| [5] |
+---------------+GENERATE_DATE_ARRAY
GENERATE_DATE_ARRAY(start_date, end_date[, INTERVAL INT64_expr date_part])Description
Returns an array of dates. The start_date and end_date
parameters determine the inclusive start and end of the array.
The GENERATE_DATE_ARRAY function accepts the following data types as inputs:
start_datemust be a DATEend_datemust be a DATEINT64_exprmust be an INT64date_partmust be either DAY, WEEK, MONTH, QUARTER, or YEAR.
The INT64_expr parameter determines the increment used to generate dates. The
default value for this parameter is 1 day.
This function returns an error if INT64_expr is set to 0.
Return Data Type
An ARRAY containing 0 or more DATE values.
Examples
The following returns an array of dates, with a default step of 1.
SELECT GENERATE_DATE_ARRAY('2016-10-05', '2016-10-08') AS example;
+--------------------------------------------------+
| example |
+--------------------------------------------------+
| [2016-10-05, 2016-10-06, 2016-10-07, 2016-10-08] |
+--------------------------------------------------+The following returns an array using a user-specified step size.
SELECT GENERATE_DATE_ARRAY(
'2016-10-05', '2016-10-09', INTERVAL 2 DAY) AS example;
+--------------------------------------+
| example |
+--------------------------------------+
| [2016-10-05, 2016-10-07, 2016-10-09] |
+--------------------------------------+The following returns an array using a negative value, -3 for its step size.
SELECT GENERATE_DATE_ARRAY('2016-10-05',
'2016-10-01', INTERVAL -3 DAY) AS example;
+--------------------------+
| example |
+--------------------------+
| [2016-10-05, 2016-10-02] |
+--------------------------+The following returns an array using the same value for the start_dateand
end_date.
SELECT GENERATE_DATE_ARRAY('2016-10-05',
'2016-10-05', INTERVAL 8 DAY) AS example;
+--------------+
| example |
+--------------+
| [2016-10-05] |
+--------------+The following returns an empty array, because the start_date is greater
than the end_date, and the step value is positive.
SELECT GENERATE_DATE_ARRAY('2016-10-05',
'2016-10-01', INTERVAL 1 DAY) AS example;
+---------+
| example |
+---------+
| [] |
+---------+The following returns a NULL array, because one of its inputs is
NULL.
SELECT GENERATE_DATE_ARRAY('2016-10-05', NULL) AS example;
+---------+
| example |
+---------+
| NULL |
+---------+The following returns an array of dates, using MONTH as the date_part
interval:
SELECT GENERATE_DATE_ARRAY('2016-01-01',
'2016-12-31', INTERVAL 2 MONTH) AS example;
+--------------------------------------------------------------------------+
| example |
+--------------------------------------------------------------------------+
| [2016-01-01, 2016-03-01, 2016-05-01, 2016-07-01, 2016-09-01, 2016-11-01] |
+--------------------------------------------------------------------------+The following uses non-constant dates to generate an array.
WITH StartsAndEnds AS (
SELECT DATE '2016-01-01' AS date_start, DATE '2016-01-31' AS date_end
UNION ALL SELECT DATE "2016-04-01", DATE "2016-04-30"
UNION ALL SELECT DATE "2016-07-01", DATE "2016-07-31"
UNION ALL SELECT DATE "2016-10-01", DATE "2016-10-31"
)
SELECT GENERATE_DATE_ARRAY(date_start, date_end, INTERVAL 1 WEEK) AS date_range
FROM StartsAndEnds;
+--------------------------------------------------------------+
| date_range |
+--------------------------------------------------------------+
| [2016-01-01, 2016-01-08, 2016-01-15, 2016-01-22, 2016-01-29] |
| [2016-04-01, 2016-04-08, 2016-04-15, 2016-04-22, 2016-04-29] |
| [2016-07-01, 2016-07-08, 2016-07-15, 2016-07-22, 2016-07-29] |
| [2016-10-01, 2016-10-08, 2016-10-15, 2016-10-22, 2016-10-29] |
+--------------------------------------------------------------+GENERATE_TIMESTAMP_ARRAY
GENERATE_TIMESTAMP_ARRAY(start_timestamp, end_timestamp,
INTERVAL step_expression date_part)Description
Returns an ARRAY of TIMESTAMPS separated by a given interval. The
start_timestamp and end_timestamp parameters determine the inclusive
lower and upper bounds of the ARRAY.
The GENERATE_TIMESTAMP_ARRAY function accepts the following data types as
inputs:
start_timestamp:TIMESTAMPend_timestamp:TIMESTAMPstep_expression:INT64- Allowed
date_partvalues areMICROSECOND,MILLISECOND,SECOND,MINUTE,HOUR, orDAY.
The step_expression parameter determines the increment used to generate
timestamps.
Return Data Type
An ARRAY containing 0 or more
TIMESTAMP values.
Examples
The following example returns an ARRAY of TIMESTAMPs at intervals of 1
second.
SELECT GENERATE_TIMESTAMP_ARRAY('2016-10-05 00:00:00', '2016-10-05 00:00:02',
INTERVAL 1 SECOND) AS timestamp_array;
+--------------------------------------------------------------------------+
| timestamp_array |
+--------------------------------------------------------------------------+
| [2016-10-05 00:00:00+00, 2016-10-05 00:00:01+00, 2016-10-05 00:00:02+00] |
+--------------------------------------------------------------------------+The following example returns an ARRAY of TIMESTAMPS with a negative
interval.
SELECT GENERATE_TIMESTAMP_ARRAY('2016-10-06 00:00:00', '2016-10-01 00:00:00',
INTERVAL -2 DAY) AS timestamp_array;
+--------------------------------------------------------------------------+
| timestamp_array |
+--------------------------------------------------------------------------+
| [2016-10-06 00:00:00+00, 2016-10-04 00:00:00+00, 2016-10-02 00:00:00+00] |
+--------------------------------------------------------------------------+The following example returns an ARRAY with a single element, because
start_timestamp and end_timestamp have the same value.
SELECT GENERATE_TIMESTAMP_ARRAY('2016-10-05 00:00:00', '2016-10-05 00:00:00',
INTERVAL 1 HOUR) AS timestamp_array;
+--------------------------+
| timestamp_array |
+--------------------------+
| [2016-10-05 00:00:00+00] |
+--------------------------+The following example returns an empty ARRAY, because start_timestamp is
later than end_timestamp.
SELECT GENERATE_TIMESTAMP_ARRAY('2016-10-06 00:00:00', '2016-10-05 00:00:00',
INTERVAL 1 HOUR) AS timestamp_array;
+-----------------+
| timestamp_array |
+-----------------+
| [] |
+-----------------+The following example returns a null ARRAY, because one of the inputs is
NULL.
SELECT GENERATE_TIMESTAMP_ARRAY('2016-10-05 00:00:00', NULL, INTERVAL 1 HOUR)
AS timestamp_array;
+-----------------+
| timestamp_array |
+-----------------+
| NULL |
+-----------------+The following example generates ARRAYs of TIMESTAMPs from columns containing
values for start_timestamp and end_timestamp.
SELECT GENERATE_TIMESTAMP_ARRAY(start_timestamp, end_timestamp, INTERVAL 1 HOUR)
AS timestamp_array
FROM
(SELECT
TIMESTAMP '2016-10-05 00:00:00' AS start_timestamp,
TIMESTAMP '2016-10-05 02:00:00' AS end_timestamp
UNION ALL
SELECT
TIMESTAMP '2016-10-05 12:00:00' AS start_timestamp,
TIMESTAMP '2016-10-05 14:00:00' AS end_timestamp
UNION ALL
SELECT
TIMESTAMP '2016-10-05 23:59:00' AS start_timestamp,
TIMESTAMP '2016-10-06 01:59:00' AS end_timestamp);
+--------------------------------------------------------------------------+
| timestamp_array |
+--------------------------------------------------------------------------+
| [2016-10-05 00:00:00+00, 2016-10-05 01:00:00+00, 2016-10-05 02:00:00+00] |
| [2016-10-05 12:00:00+00, 2016-10-05 13:00:00+00, 2016-10-05 14:00:00+00] |
| [2016-10-05 23:59:00+00, 2016-10-06 00:59:00+00, 2016-10-06 01:59:00+00] |
+--------------------------------------------------------------------------+OFFSET and ORDINAL
array_expression[OFFSET(zero_based_offset)]
array_expression[ORDINAL(one_based_offset)]Description
Accesses an ARRAY element by position and returns the
element. OFFSET means that the numbering starts at zero, ORDINAL means that
the numbering starts at one.
A given array can be interpreted as either 0-based or 1-based. When accessing an
array element, you must preface the array position with OFFSET or ORDINAL,
respectively; there is no default behavior.
Both OFFSET and ORDINAL generate an error if the index is out of range.
Return type
Varies depending on the elements in the ARRAY.
Examples
WITH items AS
(SELECT ["apples", "bananas", "pears", "grapes"] as list
UNION ALL
SELECT ["coffee", "tea", "milk" ] as list
UNION ALL
SELECT ["cake", "pie"] as list)
SELECT list, list[OFFSET(1)] as offset_1, list[ORDINAL(1)] as ordinal_1
FROM items;
+----------------------------------+-----------+-----------+
| list | offset_1 | ordinal_1 |
+----------------------------------+-----------+-----------+
| [apples, bananas, pears, grapes] | bananas | apples |
| [coffee, tea, milk] | tea | coffee |
| [cake, pie] | pie | cake |
+----------------------------------+-----------+-----------+ARRAY_REVERSE
ARRAY_REVERSE(value)Description
Returns the input ARRAY with elements in reverse order.
Return type
ARRAY
Examples
WITH example AS (
SELECT [1, 2, 3] AS arr UNION ALL
SELECT [4, 5] AS arr UNION ALL
SELECT [] AS arr
)
SELECT
arr,
ARRAY_REVERSE(arr) AS reverse_arr
FROM example;
+-----------+-------------+
| arr | reverse_arr |
+-----------+-------------+
| [1, 2, 3] | [3, 2, 1] |
| [4, 5] | [5, 4] |
| [] | [] |
+-----------+-------------+SAFE_OFFSET and SAFE_ORDINAL
array_expression[SAFE_OFFSET(zero_based_offset)]
array_expression[SAFE_ORDINAL(one_based_offset)]Description
Identical to OFFSET and ORDINAL, except returns NULL if the index is out
of range.
Return type
Varies depending on the elements in the ARRAY.
Example
WITH items AS
(SELECT ["apples", "bananas", "pears", "grapes"] as list
UNION ALL
SELECT ["coffee", "tea", "milk" ] as list
UNION ALL
SELECT ["cake", "pie"] as list)
SELECT list,
list[SAFE_OFFSET(3)] as safe_offset_3,
list[SAFE_ORDINAL(3)] as safe_ordinal_3
FROM items;
+----------------------------------+---------------+----------------+
| list | safe_offset_3 | safe_ordinal_3 |
+----------------------------------+---------------+----------------+
| [apples, bananas, pears, grapes] | grapes | pears |
| [coffee, tea, milk] | NULL | milk |
| [cake, pie] | NULL | NULL |
+----------------------------------+---------------+----------------+Date functions
BigQuery supports the following DATE functions.
CURRENT_DATE
CURRENT_DATE([time_zone])Description
Returns the current date as of the specified or default timezone.
This function supports an optional time_zone parameter. This parameter is a
string representing the timezone to use. If no timezone is specified, the
default timezone, UTC, is used. See
Timezone definitions for information on how to
specify a time zone.
If the time_zone parameter evaluates to NULL, this function returns NULL.
Return Data Type
DATE
Example
SELECT CURRENT_DATE() as the_date;
+--------------+
| the_date |
+--------------+
| 2016-12-25 |
+--------------+EXTRACT
EXTRACT(part FROM date_expression)Description
Returns the value corresponding to the specified date part. The part must
be one of:
DAYOFWEEK: Returns values in the range [1,7] with Sunday as the first day of the week.DAYDAYOFYEAR-
WEEK: Returns the week number of the date in the range [0, 53]. Weeks begin with Sunday, and dates prior to the first Sunday of the year are in week 0. -
WEEK(<WEEKDAY>): Returns the week number of the date in the range [0, 53]. Weeks begin onWEEKDAY. Dates prior to the firstWEEKDAYof the year are in week 0. Valid values forWEEKDAYareSUNDAY,MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY, andSATURDAY. ISOWEEK: Returns the ISO 8601 week number of thedate_expression.ISOWEEKs begin on Monday. Return values are in the range [1, 53]. The firstISOWEEKof each ISO year begins on the Monday before the first Thursday of the Gregorian calendar year.MONTHQUARTER: Returns values in the range [1,4].YEARISOYEAR: Returns the ISO 8601 week-numbering year, which is the Gregorian calendar year containing the Thursday of the week to whichdate_expressionbelongs.
Return Data Type
INT64
Examples
In the following example, EXTRACT returns a value corresponding to the DAY
time part.
SELECT EXTRACT(DAY FROM DATE '2013-12-25') as the_day;
+---------+
| the_day |
+---------+
| 25 |
+---------+In the following example, EXTRACT returns values corresponding to different
time parts from a column of dates near the end of the year.
SELECT
date,
EXTRACT(ISOYEAR FROM date) AS isoyear,
EXTRACT(ISOWEEK FROM date) AS isoweek,
EXTRACT(YEAR FROM date) AS year,
EXTRACT(WEEK FROM date) AS week
FROM UNNEST(GENERATE_DATE_ARRAY('2015-12-23', '2016-01-09')) AS date
ORDER BY date;
+------------+---------+---------+------+------+
| date | isoyear | isoweek | year | week |
+------------+---------+---------+------+------+
| 2015-12-23 | 2015 | 52 | 2015 | 51 |
| 2015-12-24 | 2015 | 52 | 2015 | 51 |
| 2015-12-25 | 2015 | 52 | 2015 | 51 |
| 2015-12-26 | 2015 | 52 | 2015 | 51 |
| 2015-12-27 | 2015 | 52 | 2015 | 52 |
| 2015-12-28 | 2015 | 53 | 2015 | 52 |
| 2015-12-29 | 2015 | 53 | 2015 | 52 |
| 2015-12-30 | 2015 | 53 | 2015 | 52 |
| 2015-12-31 | 2015 | 53 | 2015 | 52 |
| 2016-01-01 | 2015 | 53 | 2016 | 0 |
| 2016-01-02 | 2015 | 53 | 2016 | 0 |
| 2016-01-03 | 2015 | 53 | 2016 | 1 |
| 2016-01-04 | 2016 | 1 | 2016 | 1 |
| 2016-01-05 | 2016 | 1 | 2016 | 1 |
| 2016-01-06 | 2016 | 1 | 2016 | 1 |
| 2016-01-07 | 2016 | 1 | 2016 | 1 |
| 2016-01-08 | 2016 | 1 | 2016 | 1 |
| 2016-01-09 | 2016 | 1 | 2016 | 1 |
+------------+---------+---------+------+------+In the following example, date_expression falls on a Sunday. EXTRACT
calculates the first column using weeks that begin on Sunday, and it calculates
the second column using weeks that begin on Monday.
WITH table AS (SELECT DATE('2017-11-05') AS date)
SELECT
date,
EXTRACT(WEEK(SUNDAY) FROM date) AS week_sunday,
EXTRACT(WEEK(MONDAY) FROM date) AS week_monday FROM table;
+------------+-------------+-------------+
| date | week_sunday | week_monday |
+------------+-------------+-------------+
| 2017-11-05 | 45 | 44 |
+------------+-------------+-------------+DATE
1. DATE(year, month, day)
2. DATE(timestamp_expression[, timezone])Description
- Constructs a DATE from INT64 values representing the year, month, and day.
- Converts a
timestamp_expressionto a DATE data type. It supports an optional parameter to specify a timezone. If no timezone is specified, the default timezone, UTC, is used.
Return Data Type
DATE
Example
SELECT
DATE(2016, 12, 25) as date_ymd,
DATE(TIMESTAMP "2016-12-25 05:30:00+07", "America/Los_Angeles") as date_tstz;
+------------+------------+
| date_ymd | date_tstz |
+------------+------------+
| 2016-12-25 | 2016-12-24 |
+------------+------------+DATE_ADD
DATE_ADD(date_expression, INTERVAL INT64_expr date_part)Description
Adds a specified time interval to a DATE.
DATE_ADD supports the following date_part values:
DAYWEEK. Equivalent to 7DAYs.MONTHQUARTERYEAR
Special handling is required for MONTH, QUARTER, and YEAR parts when the date is at (or near) the last day of the month. If the resulting month has fewer days than the original date's day, then the result day is the last day of the new month.
Return Data Type
DATE
Example
SELECT DATE_ADD(DATE "2008-12-25", INTERVAL 5 DAY) as five_days_later;
+--------------------+
| five_days_later |
+--------------------+
| 2008-12-30 |
+--------------------+DATE_SUB
DATE_SUB(date_expression, INTERVAL INT64_expr date_part)Description
Subtracts a specified time interval from a DATE.
DATE_SUB supports the following date_part values:
DAYWEEK. Equivalent to 7DAYs.MONTHQUARTERYEAR
Special handling is required for MONTH, QUARTER, and YEAR parts when the date is at (or near) the last day of the month. If the resulting month has fewer days than the original date's day, then the result day is the last day of the new month.
Return Data Type
DATE
Example
SELECT DATE_SUB(DATE "2008-12-25", INTERVAL 5 DAY) as five_days_ago;
+---------------+
| five_days_ago |
+---------------+
| 2008-12-20 |
+---------------+DATE_DIFF
DATE_DIFF(date_expression, date_expression, date_part)Description
Returns the number of date_part boundaries between the two date_expressions.
If the first date occurs before the second date, then the result is
non-positive.
DATE_DIFF supports the following date_part values:
DAYWEEKThis date part begins on Sunday.WEEK(<WEEKDAY>): This date part begins onWEEKDAY. Valid values forWEEKDAYareSUNDAY,MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY, andSATURDAY.ISOWEEK: Uses ISO 8601 week boundaries. ISO weeks begin on Monday.MONTHQUARTERYEARISOYEAR: Uses the ISO 8601 week-numbering year boundary. The ISO year boundary is the Monday of the first week whose Thursday belongs to the corresponding Gregorian calendar year.
Return Data Type
INT64
Example
SELECT DATE_DIFF(DATE '2010-07-07', DATE '2008-12-25', DAY) as days_diff;
+-----------+
| days_diff |
+-----------+
| 559 |
+-----------+SELECT
DATE_DIFF(DATE '2017-10-15', DATE '2017-10-14', DAY) as days_diff,
DATE_DIFF(DATE '2017-10-15', DATE '2017-10-14', WEEK) as weeks_diff;
+-----------+------------+
| days_diff | weeks_diff |
+-----------+------------+
| 1 | 1 |
+-----------+------------+The example above shows the result of DATE_DIFF for two days in succession.
DATE_DIFF with the date part WEEK returns 1 because DATE_DIFF counts the
number of date part boundaries in this range of dates. Each WEEK begins on
Sunday, so there is one date part boundary between Saturday, 2017-10-14
and Sunday, 2017-10-15.
The following example shows the result of DATE_DIFF for two dates in different
years. DATE_DIFF with the date part YEAR returns 3 because it counts the
number of Gregorian calendar year boundaries between the two dates. DATE_DIFF
with the date part ISOYEAR returns 2 because the second date belongs to the
ISO year 2015. The first Thursday of the 2015 calendar year was 2015-01-01, so
the ISO year 2015 begins on the preceding Monday, 2014-12-29.
SELECT
DATE_DIFF('2017-12-30', '2014-12-30', YEAR) AS year_diff,
DATE_DIFF('2017-12-30', '2014-12-30', ISOYEAR) AS isoyear_diff;
+-----------+--------------+
| year_diff | isoyear_diff |
+-----------+--------------+
| 3 | 2 |
+-----------+--------------+The following example shows the result of DATE_DIFF for two days in
succession. The first date falls on a Monday and the second date falls on a
Sunday. DATE_DIFF with the date part WEEK returns 0 because this time part
uses weeks that begin on Sunday. DATE_DIFF with the date part WEEK(MONDAY)
returns 1. DATE_DIFF with the date part ISOWEEK also returns 1 because
ISO weeks begin on Monday.
SELECT
DATE_DIFF('2017-12-18', '2017-12-17', WEEK) AS week_diff,
DATE_DIFF('2017-12-18', '2017-12-17', WEEK(MONDAY)) AS week_weekday_diff,
DATE_DIFF('2017-12-18', '2017-12-17', ISOWEEK) AS isoweek_diff;
+-----------+-------------------+--------------+
| week_diff | week_weekday_diff | isoweek_diff |
+-----------+-------------------+--------------+
| 0 | 1 | 1 |
+-----------+-------------------+--------------+DATE_TRUNC
DATE_TRUNC(date_expression, date_part)Description
Truncates the date to the specified granularity.
DATE_TRUNC supports the following values for date_part:
DAYWEEKWEEK(<WEEKDAY>): Truncatesdate_expressionto the preceding week boundary, where weeks begin onWEEKDAY. Valid values forWEEKDAYareSUNDAY,MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY, andSATURDAY.ISOWEEK: Truncatesdate_expressionto the preceding ISO 8601 week boundary.ISOWEEKs begin on Monday. The firstISOWEEKof each ISO year contains the first Thursday of the corresponding Gregorian calendar year. Anydate_expressionearlier than this will truncate to the preceding Monday.MONTHQUARTERYEARISOYEAR: Truncatesdate_expressionto the preceding ISO 8601 week-numbering year boundary. The ISO year boundary is the Monday of the first week whose Thursday belongs to the corresponding Gregorian calendar year.
Return Data Type
DATE
Examples
SELECT DATE_TRUNC(DATE '2008-12-25', MONTH) as month;
+------------+
| month |
+------------+
| 2008-12-01 |
+------------+In the following example, the original date falls on a Sunday. Because
the date_part is WEEK(MONDAY), DATE_TRUNC returns the DATE for the
preceding Monday.
SELECT date AS original, DATE_TRUNC(date, WEEK(MONDAY)) AS truncated
FROM (SELECT DATE('2017-11-05') AS date);
+------------+------------+
| original | truncated |
+------------+------------+
| 2017-11-05 | 2017-10-30 |
+------------+------------+In the following example, the original date_expression is in the Gregorian
calendar year 2015. However, DATE_TRUNC with the ISOYEAR date part
truncates the date_expression to the beginning of the ISO year, not the
Gregorian calendar year. The first Thursday of the 2015 calendar year was
2015-01-01, so the ISO year 2015 begins on the preceding Monday, 2014-12-29.
Therefore the ISO year boundary preceding the date_expression 2015-06-15 is
2014-12-29.
SELECT
DATE_TRUNC('2015-06-15', ISOYEAR) AS isoyear_boundary,
EXTRACT(ISOYEAR FROM DATE '2015-06-15') AS isoyear_number;
+------------------+----------------+
| isoyear_boundary | isoyear_number |
+------------------+----------------+
| 2014-12-29 | 2015 |
+------------------+----------------+DATE_FROM_UNIX_DATE
DATE_FROM_UNIX_DATE(INT64_expression)Description
Interprets INT64_expression as the number of days since 1970-01-01.
Return Data Type
DATE
Example
SELECT DATE_FROM_UNIX_DATE(14238) as date_from_epoch;
+-----------------+
| date_from_epoch |
+-----------------+
| 2008-12-25 |
+-----------------+FORMAT_DATE
FORMAT_DATE(format_string, date_expr)Description
Formats the date_expr according to the specified format_string.
See Supported Format Elements For DATE for a list of format elements that this function supports.
Return Data Type
STRING
Example
SELECT FORMAT_DATE("%x", DATE "2008-12-25") as US_format;
+------------+
| US_format |
+------------+
| 12/25/08 |
+------------+PARSE_DATE
PARSE_DATE(format_string, date_string)Description
Uses a format_string and a string representation of a date to return a DATE
object.
When using PARSE_DATE, keep the following in mind:
- Unspecified fields. Any unspecified field is initialized from
1970-01-01. - Case insensitive names. Names, such as
Monday,February, and so on, are case insensitive. - Whitespace. One or more consecutive white spaces in the format string matches zero or more consecutive white spaces in the date string. In addition, leading and trailing white spaces in the date string are always allowed -- even if they are not in the format string.
- Format precedence. When two (or more) format elements have overlapping
information (for example both
%Fand%Yaffect the year), the last one generally overrides any earlier ones.
See Supported Format Elements For DATE for a list of format elements that this function supports.
Return Data Type
DATE
Example
SELECT PARSE_DATE("%x", "12/25/08") as parsed;
+------------+
| parsed |
+------------+
| 2008-12-25 |
+------------+UNIX_DATE
UNIX_DATE(date_expression)Description
Returns the number of days since 1970-01-01.
Return Data Type
INT64
Example
SELECT UNIX_DATE(DATE "2008-12-25") as days_from_epoch;
+-----------------+
| days_from_epoch |
+-----------------+
| 14238 |
+-----------------+Supported Format Elements for DATE
Unless otherwise noted, DATE functions that use format strings support the following elements:
| Format element | Description |
| %A | The full weekday name. |
| %a | The abbreviated weekday name. |
| %B | The full month name. |
| %b or %h | The abbreviated month name. |
| %C | The century (a year divided by 100 and truncated to an integer) as a decimal number (00-99). |
| %D | The date in the format %m/%d/%y. |
| %d | The day of the month as a decimal number (01-31). |
| %e | The day of month as a decimal number (1-31); single digits are preceded by a space. |
| %F | The date in the format %Y-%m-%d. |
| %G | The ISO 8601 year with century as a decimal number. Each ISO year begins on the Monday before the first Thursday of the Gregorian calendar year. Note that %G and %Y may produce different results near Gregorian year boundaries, where the Gregorian year and ISO year can diverge. |
| %g | The ISO 8601 year without century as a decimal number (00-99). Each ISO year begins on the Monday before the first Thursday of the Gregorian calendar year. Note that %g and %y may produce different results near Gregorian year boundaries, where the Gregorian year and ISO year can diverge. |
| %j | The day of the year as a decimal number (001-366). |
| %m | The month as a decimal number (01-12). |
| %n | A newline character. |
| %t | A tab character. |
| %U | The week number of the year (Sunday as the first day of the week) as a decimal number (00-53). |
| %u | The weekday (Monday as the first day of the week) as a decimal number (1-7). |
| %V | The week number of the year (Monday as the first day of the week) as a decimal number (01-53). If the week containing January 1 has four or more days in the new year, then it is week 1; otherwise it is week 53 of the previous year, and the next week is week 1. |
| %W | The week number of the year (Monday as the first day of the week) as a decimal number (00-53). |
| %w | The weekday (Sunday as the first day of the week) as a decimal number (0-6). |
| %x | The date representation in MM/DD/YY format. |
| %Y | The year with century as a decimal number. |
| %y | The year without century as a decimal number (00-99), with an optional leading zero. Can be mixed with %C. If %C is not specified, years 00-68 are 2000s, while years 69-99 are 1900s. |
| %E4Y | Four-character years (0001 ... 9999). Note that %Y produces as many characters as it takes to fully render the year. |
DateTime functions
BigQuery supports the following DATETIME functions.
CURRENT_DATETIME
CURRENT_DATETIME([timezone])Description
Returns the current time as a DATETIME object.
This function supports an optional timezone parameter.
See Timezone definitions for information on how to
specify a time zone.
Return Data Type
DATETIME
Example
SELECT CURRENT_DATETIME() as now;
+----------------------------+
| now |
+----------------------------+
| 2016-05-19 10:38:47.046465 |
+----------------------------+DATETIME
1. DATETIME(year, month, day, hour, minute, second)
2. DATETIME(date_expression, time_expression)
3. DATETIME(timestamp_expression [, timezone])Description
- Constructs a DATETIME object using INT64 values representing the year, month, day, hour, minute, and second.
- Constructs a DATETIME object using a DATE object and a TIME object.
- Constructs a DATETIME object using a TIMESTAMP object. It supports an optional parameter to specify a timezone. If no timezone is specified, the default timezone, UTC, is used.
Return Data Type
DATETIME
Example
SELECT
DATETIME(2008, 12, 25, 05, 30, 00) as datetime_ymdhms,
DATETIME(TIMESTAMP "2008-12-25 05:30:00+00", "America/Los_Angeles") as datetime_tstz;
+---------------------+---------------------+
| datetime_ymdhms | datetime_tstz |
+---------------------+---------------------+
| 2008-12-25 05:30:00 | 2008-12-24 21:30:00 |
+---------------------+---------------------+DATETIME_ADD
DATETIME_ADD(datetime_expression, INTERVAL INT64_expr part)Description
Adds INT64_expr units of part to the DATETIME object.
DATETIME_ADD supports the following values for part:
MICROSECONDMILLISECONDSECONDMINUTEHOURDAYWEEK. Equivalent to 7DAYs.MONTHQUARTERYEAR
Special handling is required for MONTH, QUARTER, and YEAR parts when the date is at (or near) the last day of the month. If the resulting month has fewer days than the original DATETIME's day, then the result day is the last day of the new month.
Return Data Type
DATETIME
Example
SELECT
DATETIME "2008-12-25 15:30:00" as original_date,
DATETIME_ADD(DATETIME "2008-12-25 15:30:00", INTERVAL 10 MINUTE) as later;
+-----------------------------+------------------------+
| original_date | later |
+-----------------------------+------------------------+
| 2008-12-25 15:30:00 | 2008-12-25 15:40:00 |
+-----------------------------+------------------------+DATETIME_SUB
DATETIME_SUB(datetime_expression, INTERVAL INT64_expr part)Description
Subtracts INT64_expr units of part from the DATETIME.
DATETIME_SUB supports the following values for part:
MICROSECONDMILLISECONDSECONDMINUTEHOURDAYWEEK. Equivalent to 7DAYs.MONTHQUARTERYEAR
Special handling is required for MONTH, QUARTER, and YEAR parts when the date is at (or near) the last day of the month. If the resulting month has fewer days than the original DATETIME's day, then the result day is the last day of the new month.
Return Data Type
DATETIME
Example
SELECT
DATETIME "2008-12-25 15:30:00" as original_date,
DATETIME_SUB(DATETIME "2008-12-25 15:30:00", INTERVAL 10 MINUTE) as earlier;
+-----------------------------+------------------------+
| original_date | earlier |
+-----------------------------+------------------------+
| 2008-12-25 15:30:00 | 2008-12-25 15:20:00 |
+-----------------------------+------------------------+DATETIME_DIFF
DATETIME_DIFF(datetime_expression, datetime_expression, part)Description
Returns the number of part boundaries between the two datetime_expressions.
If the first DATETIME occurs before the second DATETIME, then the result is
non-positive. Throws an error if the computation overflows the result type, such
as if the difference in microseconds between the two DATETIME objects would
overflow an INT64 value.
DATETIME_DIFF supports the following values for part:
MICROSECONDMILLISECONDSECONDMINUTEHOURDAYWEEK: This date part begins on Sunday.WEEK(<WEEKDAY>): This date part begins onWEEKDAY. Valid values forWEEKDAYareSUNDAY,MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY, andSATURDAY.ISOWEEK: Uses ISO 8601 week boundaries. ISO weeks begin on Monday.MONTHQUARTERYEARISOYEAR: Uses the ISO 8601 week-numbering year boundary. The ISO year boundary is the Monday of the first week whose Thursday belongs to the corresponding Gregorian calendar year.
Return Data Type
INT64
Example
SELECT
DATETIME "2010-07-07 10:20:00" as first_datetime,
DATETIME "2008-12-25 15:30:00" as second_datetime,
DATETIME_DIFF(DATETIME "2010-07-07 10:20:00",
DATETIME "2008-12-25 15:30:00", DAY) as difference;
+----------------------------+------------------------+------------------------+
| first_datetime | second_datetime | difference |
+----------------------------+------------------------+------------------------+
| 2010-07-07 10:20:00 | 2008-12-25 15:30:00 | 559 |
+----------------------------+------------------------+------------------------+SELECT
DATETIME_DIFF(DATETIME '2017-10-15 00:00:00',
DATETIME '2017-10-14 00:00:00', DAY) as days_diff,
DATETIME_DIFF(DATETIME '2017-10-15 00:00:00',
DATETIME '2017-10-14 00:00:00', WEEK) as weeks_diff;
+-----------+------------+
| days_diff | weeks_diff |
+-----------+------------+
| 1 | 1 |
+-----------+------------+The example above shows the result of DATETIME_DIFF for two DATETIMEs that
are 24 hours apart. DATETIME_DIFF with the part WEEK returns 1 because
DATETIME_DIFF counts the number of part boundaries in this range of
DATETIMEs. Each WEEK begins on Sunday, so there is one part boundary between
Saturday, 2017-10-14 00:00:00 and Sunday, 2017-10-15 00:00:00.
The following example shows the result of DATETIME_DIFF for two dates in
different years. DATETIME_DIFF with the date part YEAR returns 3 because it
counts the number of Gregorian calendar year boundaries between the two
DATETIMEs. DATETIME_DIFF with the date part ISOYEAR returns 2 because the
second DATETIME belongs to the ISO year 2015. The first Thursday of the 2015
calendar year was 2015-01-01, so the ISO year 2015 begins on the preceding
Monday, 2014-12-29.
SELECT
DATETIME_DIFF('2017-12-30 00:00:00',
'2014-12-30 00:00:00', YEAR) AS year_diff,
DATETIME_DIFF('2017-12-30 00:00:00',
'2014-12-30 00:00:00', ISOYEAR) AS isoyear_diff;
+-----------+--------------+
| year_diff | isoyear_diff |
+-----------+--------------+
| 3 | 2 |
+-----------+--------------+The following example shows the result of DATETIME_DIFF for two days in
succession. The first date falls on a Monday and the second date falls on a
Sunday. DATETIME_DIFF with the date part WEEK returns 0 because this time
part uses weeks that begin on Sunday. DATETIME_DIFF with the date part
WEEK(MONDAY) returns 1. DATETIME_DIFF with the date part
ISOWEEK also returns 1 because ISO weeks begin on Monday.
SELECT
DATETIME_DIFF('2017-12-18', '2017-12-17', WEEK) AS week_diff,
DATETIME_DIFF('2017-12-18', '2017-12-17', WEEK(MONDAY)) AS week_weekday_diff,
DATETIME_DIFF('2017-12-18', '2017-12-17', ISOWEEK) AS isoweek_diff;
+-----------+-------------------+--------------+
| week_diff | week_weekday_diff | isoweek_diff |
+-----------+-------------------+--------------+
| 0 | 1 | 1 |
+-----------+-------------------+--------------+DATETIME_TRUNC
DATETIME_TRUNC(datetime_expression, part)Description
Truncates a DATETIME object to the granularity of part.
DATETIME_TRUNC supports the following values for part:
MICROSECONDMILLISECONDSECONDMINUTEHOURDAYWEEKWEEK(<WEEKDAY>): Truncatesdatetime_expressionto the preceding week boundary, where weeks begin onWEEKDAY. Valid values forWEEKDAYareSUNDAY,MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY, andSATURDAY.ISOWEEK: Truncatesdatetime_expressionto the preceding ISO 8601 week boundary.ISOWEEKs begin on Monday. The firstISOWEEKof each ISO year contains the first Thursday of the corresponding Gregorian calendar year. Anydate_expressionearlier than this will truncate to the preceding Monday.MONTHQUARTERYEARISOYEAR: Truncatesdatetime_expressionto the preceding ISO 8601 week-numbering year boundary. The ISO year boundary is the Monday of the first week whose Thursday belongs to the corresponding Gregorian calendar year.
Return Data Type
DATETIME
Examples
SELECT
DATETIME "2008-12-25 15:30:00" as original,
DATETIME_TRUNC(DATETIME "2008-12-25 15:30:00", DAY) as truncated;
+----------------------------+------------------------+
| original | truncated |
+----------------------------+------------------------+
| 2008-12-25 15:30:00 | 2008-12-25 00:00:00 |
+----------------------------+------------------------+In the following example, the original DATETIME falls on a Sunday. Because the
part is WEEK(MONDAY), DATE_TRUNC returns the DATETIME for the
preceding Monday.
SELECT
datetime AS original,
DATETIME_TRUNC(datetime, WEEK(MONDAY)) AS truncated
FROM (SELECT DATETIME(TIMESTAMP '2017-11-05 00:00:00') AS datetime);
+---------------------+---------------------+
| original | truncated |
+---------------------+---------------------+
| 2017-11-05 00:00:00 | 2017-10-30 00:00:00 |
+---------------------+---------------------+In the following example, the original datetime_expression is in the Gregorian
calendar year 2015. However, DATETIME_TRUNC with the ISOYEAR date part
truncates the datetime_expression to the beginning of the ISO year, not the
Gregorian calendar year. The first Thursday of the 2015 calendar year was
2015-01-01, so the ISO year 2015 begins on the preceding Monday, 2014-12-29.
Therefore the ISO year boundary preceding the datetime_expression
2015-06-15 00:00:00 is 2014-12-29.
SELECT
DATETIME_TRUNC('2015-06-15 00:00:00', ISOYEAR) AS isoyear_boundary,
EXTRACT(ISOYEAR FROM DATETIME '2015-06-15 00:00:00') AS isoyear_number;
+---------------------+----------------+
| isoyear_boundary | isoyear_number |
+---------------------+----------------+
| 2014-12-29 00:00:00 | 2015 |
+---------------------+----------------+FORMAT_DATETIME
FORMAT_DATETIME(format_string, datetime_expression)Description
Formats a DATETIME object according to the specified format_string. See
Supported Format Elements For DATETIME
for a list of format elements that this function supports.
Return Data Type
STRING
Example
SELECT
FORMAT_DATETIME("%c", DATETIME "2008-12-25 15:30:00")
AS formatted;PARSE_DATETIME
PARSE_DATETIME(format_string, string)Description
Uses a format_string and a STRING representation
of a DATETIME to return a
DATETIME. See
Supported Format Elements For DATETIME
for a list of format elements that this function supports.
PARSE_DATETIME parses string according to the following rules:
- Unspecified fields. Any unspecified field is initialized from
1970-01-01 00:00:00.0. For example, if the year is unspecified then it defaults to1970. - Case insensitive names. Names, such as
MondayandFebruary, are case insensitive. - Whitespace. One or more consecutive white spaces in the format string
matches zero or more consecutive white spaces in the
DATETIMEstring. Leading and trailing white spaces in theDATETIMEstring are always allowed—even if they are not in the format string. - Format precedence. When two or more format elements have overlapping
information, the last one generally overrides any earlier ones, with some
exceptions. For example, both
%Fand%Yaffect the year, so the earlier element overrides the later. See the descriptions of%s,%C, and%yin Supported Format Elements For DATETIME.
Examples
The following example parses a STRING literal as a
DATETIME.
SELECT PARSE_DATETIME('%Y-%m-%d %H:%M:%S', '1998-10-18 13:45:55') AS datetime;The above query returns the following output:
+---------------------+
| datetime |
+---------------------+
| 1998-10-18 13:45:55 |
+---------------------+The following example parses a STRING literal
containing a date in a natural language format as a
DATETIME.
SELECT PARSE_DATETIME('%A, %B %e, %Y','Wednesday, December 19, 2018')
AS datetime;The above query returns the following output:
+---------------------+
| datetime |
+---------------------+
| 2018-12-19 00:00:00 |
+---------------------+Return Data Type
DATETIME
Supported format elements for DATETIME
Unless otherwise noted, DATETIME functions that use format strings support the following elements:
| Format element | Description |
| %A | The full weekday name. |
| %a | The abbreviated weekday name. |
| %B | The full month name. |
| %b or %h | The abbreviated month name. |
| %C | The century (a year divided by 100 and truncated to an integer) as a decimal number (00-99). |
| %c | The date and time representation. |
| %D | The date in the format %m/%d/%y. |
| %d | The day of the month as a decimal number (01-31). |
| %e | The day of month as a decimal number (1-31); single digits are preceded by a space. |
| %F | The date in the format %Y-%m-%d. |
| %G | The ISO 8601 year with century as a decimal number. Each ISO year begins on the Monday before the first Thursday of the Gregorian calendar year. Note that %G and %Y may produce different results near Gregorian year boundaries, where the Gregorian year and ISO year can diverge. |
| %g | The ISO 8601 year without century as a decimal number (00-99). Each ISO year begins on the Monday before the first Thursday of the Gregorian calendar year. Note that %g and %y may produce different results near Gregorian year boundaries, where the Gregorian year and ISO year can diverge. |
| %H | The hour (24-hour clock) as a decimal number (00-23). |
| %I | The hour (12-hour clock) as a decimal number (01-12). |
| %j | The day of the year as a decimal number (001-366). |
| %k | The hour (24-hour clock) as a decimal number (0-23); single digits are preceded by a space. |
| %l | The hour (12-hour clock) as a decimal number (1-12); single digits are preceded by a space. |
| %M | The minute as a decimal number (00-59). |
| %m | The month as a decimal number (01-12). |
| %n | A newline character. |
| %P | Either am or pm. |
| %p | Either AM or PM. |
| %R | The time in the format %H:%M. |
| %r | The 12-hour clock time using AM/PM notation. |
| %S | The second as a decimal number (00-60). |
| %s | The number of seconds since 1970-01-01 00:00:00. Always overrides all other format elements, independent of where %s appears in the string. If multiple %s elements appear, then the last one takes precedence. |
| %T | The time in the format %H:%M:%S. |
| %t | A tab character. |
| %U | The week number of the year (Sunday as the first day of the week) as a decimal number (00-53). |
| %u | The weekday (Monday as the first day of the week) as a decimal number (1-7). |
| %V | The week number of the year (Monday as the first day of the week) as a decimal number (01-53). If the week containing January 1 has four or more days in the new year, then it is week 1; otherwise it is week 53 of the previous year, and the next week is week 1. |
| %W | The week number of the year (Monday as the first day of the week) as a decimal number (00-53). |
| %w | The weekday (Sunday as the first day of the week) as a decimal number (0-6). |
| %X | The time representation in HH:MM:SS format. |
| %x | The date representation in MM/DD/YY format. |
| %Y | The year with century as a decimal number. |
| %y | The year without century as a decimal number (00-99), with an optional leading zero. Can be mixed with %C. If %C is not specified, years 00-68 are 2000s, while years 69-99 are 1900s. |
| %% | A single % character. |
| %E#S | Seconds with # digits of fractional precision. |
| %E*S | Seconds with full fractional precision (a literal '*'). |
| %E4Y | Four-character years (0001 ... 9999). Note that %Y produces as many characters as it takes to fully render the year. |
Time functions
BigQuery supports the following TIME functions.
CURRENT_TIME
CURRENT_TIME()Description
Returns the current time as a TIME object.
Return Data Type
TIME
Example
SELECT CURRENT_TIME() as now;
+----------------------------+
| now |
+----------------------------+
| 15:31:38.776361 |
+----------------------------+TIME
1. TIME(hour, minute, second)
2. TIME(timestamp, [timezone])
3. TIME(datetime)Description
- Constructs a
TIMEobject usingINT64values representing the hour, minute, and second. - Constructs a
TIMEobject using aTIMESTAMPobject. It supports an optional parameter to specify a timezone. If no timezone is specified, the default timezone, UTC, is used. - Constructs a
TIMEobject using aDATETIMEobject.
Return Data Type
TIME
Example
SELECT
TIME(15, 30, 00) as time_hms,
TIME(TIMESTAMP "2008-12-25 15:30:00+08", "America/Los_Angeles") as time_tstz;
+----------+-----------+
| time_hms | time_tstz |
+----------+-----------+
| 15:30:00 | 23:30:00 |
+----------+-----------+SELECT
TIME(DATETIME "2008-12-25 15:30:00.000000") AS time_dt;
+----------+
| time_dt |
+----------+
| 15:30:00 |
+----------+TIME_ADD
TIME_ADD(time_expression, INTERVAL INT64_expr part)Description
Adds INT64_expr units of part to the TIME object.
TIME_ADD supports the following values for part:
MICROSECONDMILLISECONDSECONDMINUTEHOUR
This function automatically adjusts when values fall outside of the 00:00:00 to
24:00:00 boundary. For example, if you add an hour to 23:30:00, the returned
value is 00:30:00.
Return Data Types
TIME
Example
SELECT
TIME "15:30:00" as original_time,
TIME_ADD(TIME "15:30:00", INTERVAL 10 MINUTE) as later;
+-----------------------------+------------------------+
| original_time | later |
+-----------------------------+------------------------+
| 15:30:00 | 15:40:00 |
+-----------------------------+------------------------+TIME_SUB
TIME_SUB(time_expression, INTERVAL INT_expr part)Description
Subtracts INT64_expr units of part from the TIME object.
TIME_SUB supports the following values for part:
MICROSECONDMILLISECONDSECONDMINUTEHOUR
This function automatically adjusts when values fall outside of the 00:00:00 to
24:00:00 boundary. For example, if you subtract an hour from 00:30:00, the
returned value is 23:30:00.
Return Data Type
TIME
Example
SELECT
TIME "15:30:00" as original_date,
TIME_SUB(TIME "15:30:00", INTERVAL 10 MINUTE) as earlier;
+-----------------------------+------------------------+
| original_date | earlier |
+-----------------------------+------------------------+
| 15:30:00 | 15:20:00 |
+-----------------------------+------------------------+TIME_DIFF
TIME_DIFF(time_expression, time_expression, part)Description
Returns the number of whole specified part intervals between two
TIME objects. Throws an error if the computation overflows the result type,
such as if the difference in microseconds between the two time objects would
overflow an INT64 value.
TIME_DIFF supports the following values for part:
MICROSECONDMILLISECONDSECONDMINUTEHOUR
Return Data Type
INT64
Example
SELECT
TIME "15:30:00" as first_time,
TIME "14:35:00" as second_time,
TIME_DIFF(TIME "15:30:00", TIME "14:35:00", MINUTE) as difference;
+----------------------------+------------------------+------------------------+
| first_time | second_time | difference |
+----------------------------+------------------------+------------------------+
| 15:30:00 | 14:35:00 | 55 |
+----------------------------+------------------------+------------------------+TIME_TRUNC
TIME_TRUNC(time_expression, part)Description
Truncates a TIME object to the granularity of part.
TIME_TRUNC supports the following values for part:
MICROSECONDMILLISECONDSECONDMINUTEHOUR
Return Data Type
TIME
Example
SELECT
TIME "15:30:00" as original,
TIME_TRUNC(TIME "15:30:00", HOUR) as truncated;
+----------------------------+------------------------+
| original | truncated |
+----------------------------+------------------------+
| 15:30:00 | 15:00:00 |
+----------------------------+------------------------+FORMAT_TIME
FORMAT_TIME(format_string, time_object)Description
Formats a TIME object according to the specified format_string. See
Supported Format Elements For TIME
for a list of format elements that this function supports.
Return Data Type
STRING
Example
SELECT FORMAT_TIME("%R", TIME "15:30:00") as formatted_time;
+----------------+
| formatted_time |
+----------------+
| 15:30 |
+----------------+PARSE_TIME
PARSE_TIME(format_string, string)Description
Uses a format_string and a string to return a TIME object. See
Supported Format Elements For TIME
for a list of format elements that this function supports.
When using PARSE_TIME, keep the following in mind:
- Unspecified fields. Any unspecified field is initialized from
00:00:00.0. For instance, ifsecondsis unspecified then it defaults to00, and so on. - Whitespace. One or more consecutive white spaces in the format string matches zero or more consecutive white spaces in the TIME string. In addition, leading and trailing white spaces in the TIME string are always allowed—even if they are not in the format string.
- Format precedence. When two (or more) format elements have overlapping information, the last one generally overrides any earlier ones.
Return Data Type
TIME
Example
SELECT PARSE_TIME("%H", "15") as parsed_time;
+-------------+
| parsed_time |
+-------------+
| 15:00:00 |
+-------------+Supported format elements for TIME
Unless otherwise noted, TIME functions that use format strings support the following elements:
| Format element | Description |
| %H | The hour (24-hour clock) as a decimal number (00-23). |
| %I | The hour (12-hour clock) as a decimal number (01-12). |
| %j | The day of the year as a decimal number (001-366). |
| %k | The hour (24-hour clock) as a decimal number (0-23); single digits are preceded by a space. |
| %l | The hour (12-hour clock) as a decimal number (1-12); single digits are preceded by a space. |
| %M | The minute as a decimal number (00-59). |
| %n | A newline character. |
| %P | Either am or pm. |
| %p | Either AM or PM. |
| %R | The time in the format %H:%M. |
| %r | The 12-hour clock time using AM/PM notation. |
| %S | The second as a decimal number (00-60). |
| %T | The time in the format %H:%M:%S. |
| %t | A tab character. |
| %X | The time representation in HH:MM:SS format. |
| %% | A single % character. |
| %E#S | Seconds with # digits of fractional precision. |
| %E*S | Seconds with full fractional precision (a literal '*'). |
Timestamp functions
BigQuery supports the following TIMESTAMP functions.
NOTE: These functions return a runtime error if overflow occurs; result values are bounded by the defined date and timestamp min/max values.
CURRENT_TIMESTAMP
CURRENT_TIMESTAMP()Description
Parentheses are optional. This function handles leap seconds by smearing them
across a window of 20 hours around the inserted leap
second.
CURRENT_TIMESTAMP() produces a TIMESTAMP value that is continuous,
non-ambiguous, has exactly 60 seconds per minute and does not repeat values over
the leap second.
Supported Input Types
Not applicable
Result Data Type
TIMESTAMP
Example
SELECT CURRENT_TIMESTAMP() as now;
+-------------------------------+
| now |
+-------------------------------+
| 2016-05-16 18:12:47.145482+00 |
+-------------------------------+EXTRACT
EXTRACT(part FROM timestamp_expression [AT TIME ZONE tz_spec])Description
Returns an INT64 value that corresponds to the specified part from
a supplied timestamp_expression.
Allowed part values are:
MICROSECONDMILLISECONDSECONDMINUTEHOURDAYOFWEEKDAYDAYOFYEAR-
WEEK: Returns the week number of the date in the range [0, 53]. Weeks begin with Sunday, and dates prior to the first Sunday of the year are in week 0. -
WEEK(<WEEKDAY>): Returns the week number oftimestamp_expressionin the range [0, 53]. Weeks begin onWEEKDAY.datetimes prior to the firstWEEKDAYof the year are in week 0. Valid values forWEEKDAYareSUNDAY,MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY, andSATURDAY. -
ISOWEEK: Returns the ISO 8601 week number of thedatetime_expression.ISOWEEKs begin on Monday. Return values are in the range [1, 53]. The firstISOWEEKof each ISO year begins on the Monday before the first Thursday of the Gregorian calendar year. MONTHQUARTERYEARISOYEAR: Returns the ISO 8601 week-numbering year, which is the Gregorian calendar year containing the Thursday of the week to whichdate_expressionbelongs.DATEDATETIMETIME
Returned values truncate lower order time periods. For example, when extracting
seconds, EXTRACT truncates the millisecond and microsecond values.
See Timezone definitions for information on how to specify a time zone.
Return Data Type
Generally
INT64
. Returns
DATE if part is
DATE.
Examples
In the following example, EXTRACT returns a value corresponding to the DAY
time part.
SELECT EXTRACT(DAY
FROM TIMESTAMP "2008-12-25 15:30:00" AT TIME ZONE "America/Los_Angeles")
AS the_day;
+------------+
| the_day |
+------------+
| 25 |
+------------+In the following example, EXTRACT returns values corresponding to different
time parts from a column of timestamps.
WITH Timestamps AS (
SELECT TIMESTAMP '2005-01-03 12:34:56' AS timestamp UNION ALL
SELECT TIMESTAMP '2007-12-31' UNION ALL
SELECT TIMESTAMP '2009-01-01' UNION ALL
SELECT TIMESTAMP '2009-12-31' UNION ALL
SELECT TIMESTAMP '2017-01-02' UNION ALL
SELECT TIMESTAMP '2017-05-26'
)
SELECT
timestamp,
EXTRACT(ISOYEAR FROM timestamp) AS isoyear,
EXTRACT(ISOWEEK FROM timestamp) AS isoweek,
EXTRACT(YEAR FROM timestamp) AS year,
EXTRACT(WEEK FROM timestamp) AS week
FROM Timestamps
ORDER BY timestamp;
+------------------------+---------+---------+------+------+
| timestamp | isoyear | isoweek | year | week |
+------------------------+---------+---------+------+------+
| 2005-01-03 12:34:56+00 | 2005 | 1 | 2005 | 1 |
| 2007-12-31 00:00:00+00 | 2008 | 1 | 2007 | 52 |
| 2009-01-01 00:00:00+00 | 2009 | 1 | 2009 | 0 |
| 2009-12-31 00:00:00+00 | 2009 | 53 | 2009 | 52 |
| 2017-01-02 00:00:00+00 | 2017 | 1 | 2017 | 1 |
| 2017-05-26 00:00:00+00 | 2017 | 21 | 2017 | 21 |
+------------------------+---------+---------+------+------+In the following example, timestamp_expression falls on a Sunday. EXTRACT
calculates the first column using weeks that begin on Sunday, and it calculates
the second column using weeks that begin on Monday.
WITH table AS (SELECT TIMESTAMP('2017-11-05 00:00:00') AS timestamp)
SELECT
timestamp,
EXTRACT(WEEK(SUNDAY) FROM timestamp) AS week_sunday,
EXTRACT(WEEK(MONDAY) FROM timestamp) AS week_monday
FROM table;
+------------------------+-------------+---------------+
| timestamp | week_sunday | week_monday |
+------------------------+-------------+---------------+
| 2017-11-05 00:00:00+00 | 45 | 44 |
+------------------------+-------------+---------------+STRING
STRING(timestamp_expression[, timezone])Description
Converts a timestamp_expression to a STRING data type. Supports an optional
parameter to specify a timezone. See
Timezone definitions for information
on how to specify a time zone.
Return Data Type
STRING
Example
SELECT STRING(TIMESTAMP "2008-12-25 15:30:00", "America/Los_Angeles") as string;
+-------------------------------+
| string |
+-------------------------------+
| 2008-12-25 15:30:00-08 |
+-------------------------------+TIMESTAMP
1. TIMESTAMP(string_expression[, timezone])
2. TIMESTAMP(date_expression[, timezone])
3. TIMESTAMP(datetime_expression[, timezone])Description
-
Converts a STRING expression to a TIMESTAMP data type.
-
Converts a DATE object to a TIMESTAMP data type.
-
Converts a DATETIME object to a TIMESTAMP data type.
This function supports an optional parameter to specify a timezone. If no timezone is specified, the default timezone, UTC, is used.
Return Data Type
TIMESTAMP
Example
SELECT
CAST(TIMESTAMP("2008-12-25 15:30:00", "America/Los_Angeles") AS STRING) AS timestamp_str,
CAST(TIMESTAMP(DATE "2008-12-25", "America/Los_Angeles") AS STRING) AS timestamp_date,
CAST(TIMESTAMP(DATETIME "2008-12-25 15:30:00", "America/Los_Angeles") AS STRING) AS timestamp_datetime;
+------------------------+------------------------+------------------------+
| timestamp_str | timestamp_date | timestamp_datetime |
+------------------------+------------------------+------------------------+
| 2008-12-25 23:30:00+00 | 2008-12-25 08:00:00+00 | 2008-12-25 23:30:00+00 |
+------------------------+------------------------+------------------------+TIMESTAMP_ADD
TIMESTAMP_ADD(timestamp_expression, INTERVAL int64_expression date_part)Description
Adds int64_expression units of date_part to the timestamp, independent of
any time zone.
TIMESTAMP_ADD supports the following values for date_part:
MICROSECONDMILLISECONDSECONDMINUTEHOUR. Equivalent to 60MINUTEs.
Return Data Types
TIMESTAMP
Example
SELECT
TIMESTAMP "2008-12-25 15:30:00 UTC" as original,
TIMESTAMP_ADD(TIMESTAMP "2008-12-25 15:30:00 UTC", INTERVAL 10 MINUTE) AS later;
+------------------------+------------------------+
| original | later |
+------------------------+------------------------+
| 2008-12-25 15:30:00+00 | 2008-12-25 15:40:00+00 |
+------------------------+------------------------+TIMESTAMP_SUB
TIMESTAMP_SUB(timestamp_expression, INTERVAL int64_expression date_part)Description
Subtracts int64_expression units of date_part from the timestamp,
independent of any time zone.
TIMESTAMP_SUB supports the following values for date_part:
MICROSECONDMILLISECONDSECONDMINUTEHOUR. Equivalent to 60MINUTEs.
Return Data Type
TIMESTAMP
Example
SELECT
TIMESTAMP "2008-12-25 15:30:00 UTC" as original,
TIMESTAMP_SUB(TIMESTAMP "2008-12-25 15:30:00 UTC", INTERVAL 10 MINUTE) AS earlier;
+------------------------+------------------------+
| original | earlier |
+------------------------+------------------------+
| 2008-12-25 15:30:00+00 | 2008-12-25 15:20:00+00 |
+------------------------+------------------------+TIMESTAMP_DIFF
TIMESTAMP_DIFF(timestamp_expression, timestamp_expression, date_part)Description
Returns the number of whole specified date_part intervals between two
timestamps. The first timestamp_expression represents the later date; if the
first timestamp_expression is earlier than the second timestamp_expression,
the output is negative. Throws an error if the computation overflows the result
type, such as if the difference in
microseconds between
the two timestamps would overflow an INT64 value.
TIMESTAMP_DIFF supports the following values for date_part:
MICROSECONDMILLISECONDSECONDMINUTEHOUR. Equivalent to 60MINUTEs.
Return Data Type
INT64
Example
SELECT
TIMESTAMP "2010-07-07 10:20:00 UTC" as later_timestamp,
TIMESTAMP "2008-12-25 15:30:00 UTC" as earlier_timestamp,
TIMESTAMP_DIFF(TIMESTAMP "2010-07-07 10:20:00 UTC",
TIMESTAMP "2008-12-25 15:30:00 UTC", HOUR) AS hours;
+------------------------+------------------------+-------+
| later_timestamp | earlier_timestamp | hours |
+------------------------+------------------------+-------+
| 2010-07-07 10:20:00+00 | 2008-12-25 15:30:00+00 | 13410 |
+------------------------+------------------------+-------+In the following example, the first timestamp occurs before the second timestamp, resulting in a negative output.
SELECT TIMESTAMP_DIFF(TIMESTAMP "2018-08-14", TIMESTAMP "2018-10-14", DAY);
+---------------+
| negative_diff |
+---------------+
| -61 |
+---------------+TIMESTAMP_TRUNC
TIMESTAMP_TRUNC(timestamp_expression, date_part[, time_zone])Description
Truncates a timestamp to the granularity of date_part.
TIMESTAMP_TRUNC supports the following values for date_part:
MICROSECONDMILLISECONDSECONDMINUTEHOURDAYWEEKWEEK(<WEEKDAY>):Truncatestimestamp_expressionto the preceding week boundary, where weeks begin onWEEKDAY. Valid values forWEEKDAYareSUNDAY,MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY, andSATURDAY.ISOWEEK: Truncatestimestamp_expressionto the preceding ISO 8601 week boundary.ISOWEEKs begin on Monday. The firstISOWEEKof each ISO year contains the first Thursday of the corresponding Gregorian calendar year. Anydate_expressionearlier than this will truncate to the preceding Monday.MONTHQUARTERYEARISOYEAR: Truncatestimestamp_expressionto the preceding ISO 8601 week-numbering year boundary. The ISO year boundary is the Monday of the first week whose Thursday belongs to the corresponding Gregorian calendar year.
TIMESTAMP_TRUNC function supports an optional time_zone parameter. This
parameter applies to the following date_parts:
MINUTEHOURDAYWEEKWEEK(<WEEKDAY>)MONTHQUARTERYEAR
Use this parameter if you want to use a time zone other than the default timezone, UTC, as part of the truncate operation.
When truncating a TIMESTAMP to MINUTE
orHOUR, TIMESTAMP_TRUNC determines the civil time of the
TIMESTAMP in the specified (or default) timezone
and subtracts the minutes and seconds (when truncating to HOUR) or the seconds
(when truncating to MINUTE) from that TIMESTAMP.
While this provides intuitive results in most cases, the result is
non-intuitive near daylight savings transitions that are not hour aligned.
Return Data Type
TIMESTAMP
Examples
SELECT
TIMESTAMP_TRUNC(TIMESTAMP '2008-12-25 15:30:00', DAY, 'UTC') as utc,
TIMESTAMP_TRUNC(TIMESTAMP '2008-12-25 15:30:00', DAY, 'America/Los_Angeles') as la;
+------------------------+------------------------+
| utc | la |
+------------------------+------------------------+
| 2008-12-25 00:00:00+00 | 2008-12-25 08:00:00+00 |
+------------------------+------------------------+In the following example, timestamp_expression has a time zone offset of +12.
The first column shows the timestamp_expression in UTC time. The second
column shows the output of TIMESTAMP_TRUNC using weeks that start on Monday.
Because the timestamp_expression falls on a Sunday in UTC, TIMESTAMP_TRUNC
truncates it to the preceding Monday. The third column shows the same function
with the optional Timezone definition
argument 'Pacific/Auckland'. Here the function truncates the
timestamp_expression using New Zealand Daylight Time, where it falls on a
Monday.
SELECT
timestamp,
TIMESTAMP_TRUNC(timestamp, WEEK(MONDAY)) AS utc_truncated,
TIMESTAMP_TRUNC(timestamp, WEEK(MONDAY), 'Pacific/Auckland') AS nzdt_truncated
FROM (SELECT TIMESTAMP('2017-11-06 00:00:00+12') AS timestamp);
+------------------------+------------------------+------------------------+
| timestamp | utc_truncated | nzdt_truncated |
+------------------------+------------------------+------------------------+
| 2017-11-05 12:00:00+00 | 2017-10-30 07:00:00+00 | 2017-11-05 11:00:00+00 |
+------------------------+------------------------+------------------------+In the following example, the original timestamp_expression is in the
Gregorian calendar year 2015. However, TIMESTAMP_TRUNC with the ISOYEAR date
part truncates the timestamp_expression to the beginning of the ISO year, not
the Gregorian calendar year. The first Thursday of the 2015 calendar year was
2015-01-01, so the ISO year 2015 begins on the preceding Monday, 2014-12-29.
Therefore the ISO year boundary preceding the timestamp_expression
2015-06-15 00:00:00+00 is 2014-12-29.
SELECT
TIMESTAMP_TRUNC('2015-06-15 00:00:00+00', ISOYEAR) AS isoyear_boundary,
EXTRACT(ISOYEAR FROM TIMESTAMP '2015-06-15 00:00:00+00') AS isoyear_number;
+------------------------+----------------+
| isoyear_boundary | isoyear_number |
+------------------------+----------------+
| 2014-12-29 00:00:00+00 | 2015 |
+------------------------+----------------+FORMAT_TIMESTAMP
FORMAT_TIMESTAMP(format_string, timestamp[, time_zone])Description
Formats a timestamp according to the specified format_string.
See Supported Format Elements For TIMESTAMP for a list of format elements that this function supports.
Return Data Type
STRING
Example
SELECT FORMAT_TIMESTAMP("%c", TIMESTAMP "2008-12-25 15:30:00", "America/Los_Angeles")
AS formatted;
+--------------------------+
| formatted |
+--------------------------+
| Thu Dec 25 07:30:00 2008 |
+--------------------------+PARSE_TIMESTAMP
PARSE_TIMESTAMP(format_string, string[, time_zone])Description
Uses a format_string and a string representation of a timestamp to return a
TIMESTAMP object.
When using PARSE_TIMESTAMP, keep the following in mind:
- Unspecified fields. Any unspecified field is initialized from
1970-01-01 00:00:00.0. This initialization value uses the time zone specified by the function's time zone argument, if present. If not, the initialization value uses the default time zone, UTC. For instance, if the year is unspecified then it defaults to1970, and so on. - Case insensitive names. Names, such as
Monday,February, and so on, are case insensitive. - Whitespace. One or more consecutive white spaces in the format string matches zero or more consecutive white spaces in the timestamp string. In addition, leading and trailing white spaces in the timestamp string are always allowed -- even if they are not in the format string.
- Format precedence. When two (or more) format elements have overlapping
information (for example both
%Fand%Yaffect the year), the last one generally overrides any earlier ones, with some exceptions (see the descriptions of%s,%C, and%y).
See Supported Format Elements For TIMESTAMP for a list of format elements that this function supports.
Return Data Type
TIMESTAMP
Example
SELECT PARSE_TIMESTAMP("%c", "Thu Dec 25 07:30:00 2008", "America/Los_Angeles") as parsed;
+-------------------------+
| parsed |
+-------------------------+
| 2008-12-25 15:30:00 UTC |
+-------------------------+TIMESTAMP_SECONDS
TIMESTAMP_SECONDS(int64_expression)Description
Interprets int64_expression as the number of seconds since 1970-01-01 00:00:00
UTC.
Return Data Type
TIMESTAMP
Example
SELECT TIMESTAMP_SECONDS(1230219000) as timestamp;
+-------------------------+
| timestamp |
+-------------------------+
| 2008-12-25 15:30:00 UTC |
+-------------------------+TIMESTAMP_MILLIS
TIMESTAMP_MILLIS(int64_expression)Description
Interprets int64_expression as the number of milliseconds since 1970-01-01
00:00:00 UTC.
Return Data Type
TIMESTAMP
Example
SELECT TIMESTAMP_MILLIS(1230219000000) as timestamp;
+-------------------------+
| timestamp |
+-------------------------+
| 2008-12-25 15:30:00 UTC |
+-------------------------+TIMESTAMP_MICROS
TIMESTAMP_MICROS(int64_expression)Description
Interprets int64_expression as the number of microseconds since 1970-01-01
00:00:00 UTC.
Return Data Type
TIMESTAMP
Example
SELECT TIMESTAMP_MICROS(1230219000000000) as timestamp;
+-------------------------+
| timestamp |
+-------------------------+
| 2008-12-25 15:30:00 UTC |
+-------------------------+UNIX_SECONDS
UNIX_SECONDS(timestamp_expression)Description
Returns the number of seconds since 1970-01-01 00:00:00 UTC. Truncates higher levels of precision.
Return Data Type
INT64
Example
SELECT UNIX_SECONDS(TIMESTAMP "2008-12-25 15:30:00") as seconds;
+------------+
| seconds |
+------------+
| 1230219000 |
+------------+UNIX_MILLIS
UNIX_MILLIS(timestamp_expression)Description
Returns the number of milliseconds since 1970-01-01 00:00:00 UTC. Truncates higher levels of precision.
Return Data Type
INT64
Example
SELECT UNIX_MILLIS(TIMESTAMP "2008-12-25 15:30:00 UTC") as millis;
+---------------+
| millis |
+---------------+
| 1230219000000 |
+---------------+UNIX_MICROS
UNIX_MICROS(timestamp_expression)Description
Returns the number of microseconds since 1970-01-01 00:00:00 UTC. Truncates higher levels of precision.
Return Data Type
INT64
Example
SELECT UNIX_MICROS(TIMESTAMP "2008-12-25 15:30:00") as micros;
+------------------+
| micros |
+------------------+
| 1230219000000000 |
+------------------+Supported format elements for TIMESTAMP
Unless otherwise noted, TIMESTAMP functions that use format strings support the following elements:
| Format element | Description |
| %A | The full weekday name. |
| %a | The abbreviated weekday name. |
| %B | The full month name. |
| %b or %h | The abbreviated month name. |
| %C | The century (a year divided by 100 and truncated to an integer) as a decimal number (00-99). |
| %c | The date and time representation. |
| %D | The date in the format %m/%d/%y. |
| %d | The day of the month as a decimal number (01-31). |
| %e | The day of month as a decimal number (1-31); single digits are preceded by a space. |
| %F | The date in the format %Y-%m-%d. |
| %G | The ISO 8601 year with century as a decimal number. Each ISO year begins on the Monday before the first Thursday of the Gregorian calendar year. Note that %G and %Y may produce different results near Gregorian year boundaries, where the Gregorian year and ISO year can diverge. |
| %g | The ISO 8601 year without century as a decimal number (00-99). Each ISO year begins on the Monday before the first Thursday of the Gregorian calendar year. Note that %g and %y may produce different results near Gregorian year boundaries, where the Gregorian year and ISO year can diverge. |
| %H | The hour (24-hour clock) as a decimal number (00-23). |
| %I | The hour (12-hour clock) as a decimal number (01-12). |
| %j | The day of the year as a decimal number (001-366). |
| %k | The hour (24-hour clock) as a decimal number (0-23); single digits are preceded by a space. |
| %l | The hour (12-hour clock) as a decimal number (1-12); single digits are preceded by a space. |
| %M | The minute as a decimal number (00-59). |
| %m | The month as a decimal number (01-12). |
| %n | A newline character. |
| %P | Either am or pm. |
| %p | Either AM or PM. |
| %R | The time in the format %H:%M. |
| %r | The 12-hour clock time using AM/PM notation. |
| %S | The second as a decimal number (00-60). |
| %s | The number of seconds since 1970-01-01 00:00:00 UTC. Always overrides all other format elements, independent of where %s appears in the string. If multiple %s elements appear, then the last one takes precedence. |
| %T | The time in the format %H:%M:%S. |
| %t | A tab character. |
| %U | The week number of the year (Sunday as the first day of the week) as a decimal number (00-53). |
| %u | The weekday (Monday as the first day of the week) as a decimal number (1-7). |
| %V | The week number of the year (Monday as the first day of the week) as a decimal number (01-53). If the week containing January 1 has four or more days in the new year, then it is week 1; otherwise it is week 53 of the previous year, and the next week is week 1. |
| %W | The week number of the year (Monday as the first day of the week) as a decimal number (00-53). |
| %w | The weekday (Sunday as the first day of the week) as a decimal number (0-6). |
| %X | The time representation in HH:MM:SS format. |
| %x | The date representation in MM/DD/YY format. |
| %Y | The year with century as a decimal number. |
| %y | The year without century as a decimal number (00-99), with an optional leading zero. Can be mixed with %C. If %C is not specified, years 00-68 are 2000s, while years 69-99 are 1900s. |
| %Z | The time zone name. |
| %z | The offset from the Prime Meridian in the format +HHMM or -HHMM as appropriate, with positive values representing locations east of Greenwich. |
| %% | A single % character. |
| %Ez | RFC 3339-compatible numeric time zone (+HH:MM or -HH:MM). |
| %E#S | Seconds with # digits of fractional precision. |
| %E*S | Seconds with full fractional precision (a literal '*'). |
| %E4Y | Four-character years (0001 ... 9999). Note that %Y produces as many characters as it takes to fully render the year. |
Timezone definitions
Certain date and timestamp functions allow you to override the default time zone and specify a different one. You can specify a timezone by supplying its UTC offset using the following format:
(+|-)H[H][:M[M]]For example:
-08:00Geography functions
The geography functions operate on or generate BigQuery
GEOGRAPHY values. The signature of any geography
function starts with ST_. BigQuery supports the following functions
that can be used to analyze geographical data, determine spatial relationships
between geographical features, and construct or manipulate
GEOGRAPHYs.
The geography functions are grouped into the following categories based on their behavior:
- Constructors: Functions that build new
GEOGRAPHYvalues from coordinates or existingGEOGRAPHYs, such asST_GEOGPOINT. - Parsers: Functions that create
GEOGRAPHYs from an external format such as WKT and GeoJSON. For example,ST_GEOGFROMTEXT, creates aGEOGRAPHYfrom WKT. - Formatters: Functions that export
GEOGRAPHYs to an external format such as WKT and GeoJSON. For example,ST_ASTEXTformats aGEOGRAPHYto WKT. - Transformations: Functions that generate a new
GEOGRAPHYfrom others that adhere to some property. Examples includeST_INTERSECTIONandST_BOUNDARY. - Predicates: Functions that return
TRUEorFALSEfor some spatial relationship between twoGEOGRAPHYs, or for some property of a geography. These functions are commonly used in filter clauses. For example,ST_DWITHINis a predicate. - Accessors: Functions that provide access to properties
of a
GEOGRAPHYwithout side-effects, such asST_NUMPOINTS. - Measures: Functions that compute measurements of one or
more
GEOGRAPHY, for exampleST_DISTANCE. - Aggregate Functions: Geography-specific aggregate
functions, such as
ST_UNION_AGG.
All BigQuery geography functions return NULL if any input argument
is NULL.
ST_GEOGPOINT
ST_GEOGPOINT(longitude, latitude)Description
Creates a GEOGRAPHY with a single point.
ST_GEOGPOINT creates a point from the specified
FLOAT64 longitude and latitude parameters and
returns that point in a GEOGRAPHY value.
Constraints
- Latitudes must be in the range [-90, 90]. Latitudes outside this range will result in an error.
- Longitudes outside the range [-180, 180] are allowed;
ST_GEOGPOINTuses the input longitude modulo 360 to obtain a longitude within [-180, 180].
Return type
GEOGRAPHY
ST_MAKELINE
ST_MAKELINE(geography_1, geography_2)ST_MAKELINE(array_of_geography)Description
Creates a GEOGRAPHY with a single linestring by
concatenating the point or line vertices of each of the input
GEOGRAPHYs in the order they are given.
Input can either be two GEOGRAPHYs or an
ARRAY of type
GEOGRAPHY. Each input
GEOGRAPHY must consist of one of the following
values:
- Exactly one point.
- Exactly one linestring.
Constraints
Every edge must span strictly less than 180 degrees.
NOTE: BigQuery's snapping process may discard sufficiently short edges
and snap the two endpoints together. For instance, if two input
GEOGRAPHYs each contain a point and the two points
are separated by a distance less than the snap radius, the points will be
snapped together. In such a case the result will be a
GEOGRAPHY with exactly one point.
Return type
GEOGRAPHY
ST_MAKEPOLYGON
ST_MAKEPOLYGON(geography_expression)ST_MAKEPOLYGON(geography_expression, array_of_geography)Description
Creates a GEOGRAPHY containing a single polygon
from linestring inputs, where each input linestring is used to construct a
polygon ring.
The linestring input is either provided by a single
GEOGRAPHY containing exactly one linestring, or by
a single GEOGRAPHY and an array of
GEOGRAPHYs, each containing exactly one linestring.
The first GEOGRAPHY will always be used to
construct the polygon shell. Any additional
GEOGRAPHYs beyond the first in the array specify a
polygon hole. For every input GEOGRAPHY containing
exactly one linestring, the following must be true:
- The linestring must consist of at least three distinct vertices.
- The linestring must be closed: that is, the first and last vertex have to be the same. If the first and last vertex differ, the function constructs a final edge from the first vertex to the last.
NOTE: ST_MAKEPOLYGON accepts an empty GEOGRAPHY
as input. ST_MAKEPOLYGON interprets an empty
GEOGRAPHY as having an empty linestring, which will
create a full loop: that is, a polygon that covers the entire Earth.
Constraints
Together, the input rings must form a valid polygon:
- The polygon shell must cover each of the polygon holes.
- There can be only one polygon shell (which has to be the first input ring). This implies that polygon holes cannot be nested.
- Polygon rings may only intersect in a vertex on the boundary of both rings.
Every edge must span strictly less than 180 degrees.
Each polygon ring divides the sphere into two regions. The first input linesting
to ST_MAKEPOLYGON forms the polygon shell, and the interior is chosen to be
the smaller of the two regions. Each subsequent input linestring specifies a
polygon hole, so the interior of the polygon is already well-defined. In order
to define a polygon shell such that the interior of the polygon is the larger of
the two regions, see ST_MAKEPOLYGONORIENTED.
NOTE: BigQuery's snapping process may discard sufficiently short edges
and snap the two endpoints together. Hence, when vertices are snapped together,
it is possible that a polygon hole that is sufficiently small may disappear, or
the output GEOGRAPHY may contain only a line or a
point.
Return type
GEOGRAPHY
ST_MAKEPOLYGONORIENTED
ST_MAKEPOLYGONORIENTED(array_of_geography)Description
Like ST_MAKEPOLYGON, but the vertex ordering of each input linestring
determines the orientation of each polygon ring. The orientation of a polygon
ring defines the interior of the polygon as follows: if someone walks along the
boundary of the polygon in the order of the input vertices, the interior of the
polygon is on the left. This applies for each polygon ring provided.
This variant of the polygon constructor is more flexible since
ST_MAKEPOLYGONORIENTED can construct a polygon such that the interior is on
either side of the polygon ring. However, proper orientation of polygon rings is
critical in order to construct the desired polygon.
NOTE: The input argument for ST_MAKEPOLYGONORIENTED may contain an empty
GEOGRAPHY. ST_MAKEPOLYGONORIENTED
interprets an empty GEOGRAPHY as having an empty
linestring, which will create a full loop: that is, a polygon that covers the
entire Earth.
Constraints
Together, the input rings must form a valid polygon:
- The polygon shell must cover each of the polygon holes.
- There must be only one polygon shell, which must to be the first input ring. This implies that polygon holes cannot be nested.
- Polygon rings may only intersect in a vertex on the boundary of both rings.
Every edge must span strictly less than 180 degrees.
ST_MAKEPOLYGONORIENTED relies on the ordering of the input vertices of each
linestring to determine the orientation of the polygon. This applies to the
polygon shell and any polygon holes. ST_MAKEPOLYGONORIENTED expects all
polygon holes to have the opposite orientation of the shell. See
ST_MAKEPOLYGON for an alternate polygon constructor, and
other constraints on building a valid polygon.
NOTE: Due to BigQuery's snapping process, edges with a sufficiently
short length will be discarded and the two endpoints will be snapped to a single
point. Therefore, it is possible that vertices in a linestring may be snapped
together such that one or more edge disappears. Hence, it is possible that a
polygon hole that is sufficiently small may disappear, or the resulting
GEOGRAPHY may contain only a line or a point.
Return type
GEOGRAPHY
ST_GEOGFROMGEOJSON
ST_GEOGFROMGEOJSON(geojson_string)Description
Returns a GEOGRAPHY value that corresponds to the
input GeoJSON representation.
ST_GEOGFROMGEOJSON accepts input that is RFC 7946
compliant.
A BigQuery GEOGRAPHY has spherical
geodesic edges, whereas a GeoJSON Geometry object explicitly has planar edges.
To convert between these two types of edges, BigQuery adds additional
points to the line where necessary so that the resulting sequence of edges
remains within 10 meters of the original edge.
See ST_ASGEOJSON to format a
GEOGRAPHY as GeoJSON.
Constraints
The input is subject to the following constraints:
ST_GEOGFROMGEOJSONonly accepts JSON geometry fragments and cannot be used to ingest a whole JSON document.- The input JSON fragment must consist of a GeoJSON geometry type, which
includes
Point,MultiPoint,LineString,MultiLineString,Polygon,MultiPolygon, andGeometryCollection. Any other GeoJSON type such asFeatureorFeatureCollectionwill result in an error. - A position in the
coordinatesmember of a GeoJSON geometry type must consist of exactly two elements. The first is the longitude and the second is the latitude. Therefore,ST_GEOGFROMGEOJSONdoes not support the optional third element for a position in thecoordinatesmember.
Return type
GEOGRAPHY
ST_GEOGFROMTEXT
ST_GEOGFROMTEXT(wkt_string)ST_GEOGFROMTEXT(wkt_string, oriented)Description
Returns a GEOGRAPHY value that corresponds to the
input WKT representation.
This function supports an optional parameter of type
BOOL, oriented. If this parameter is set to
TRUE, any polygons in the input are assumed to be oriented as follows:
if someone walks along the boundary of the polygon in the order of
the input vertices, the interior of the polygon is on the left. This allows
WKT to represent polygons larger than a hemisphere. If oriented is FALSE or
omitted, this function returns the polygon with the smaller area.
See also ST_MAKEPOLYGONORIENTED which is similar
to ST_GEOGFROMTEXT with oriented=TRUE.
To format GEOGRAPHY as WKT, use
ST_ASTEXT.
Constraints
All input edges are assumed to be spherical geodesics, and not planar straight
lines. For reading data in a planar projection, consider using
ST_GEOGFROMGEOJSON. For
more information on the differences between spherical geodesics and planar
lines, see
Coordinate systems and edges.
Return type
GEOGRAPHY
Example
The following query reads the WKT string POLYGON((0 0, 0 2, 2 2, 0 2, 0 0))
both as a non-oriented polygon and as an oriented polygon, and checks whether
each result contains the point (1, 1).
WITH polygon AS (SELECT 'Polygon((0 0, 0 2, 2 2, 2 0, 0 0))' AS p)
SELECT
ST_CONTAINS(ST_GEOGFROMTEXT(p), ST_GEOGPOINT(1, 1)) AS fromtext_default,
ST_CONTAINS(ST_GEOGFROMTEXT(p, FALSE), ST_GEOGPOINT(1, 1)) AS non_oriented,
ST_CONTAINS(ST_GEOGFROMTEXT(p, TRUE), ST_GEOGPOINT(1, 1)) AS oriented
FROM polygon;
+-------------------+---------------+-----------+
| fromtext_default | non_oriented | oriented |
+-------------------+---------------+-----------+
| true | true | false |
+-------------------+---------------+-----------+ST_GEOGFROMWKB
ST_GEOGFROMWKB(wkb_bytes)Description
Returns a GEOGRAPHY value that corresponds to the
input WKB representation.
To format GEOGRAPHY as WKB, use
ST_ASBINARY.
Constraints
All input edges are assumed to be spherical geodesics, and not planar straight
lines. For reading data in a planar projection, consider using
ST_GEOGFROMGEOJSON.
Return type
GEOGRAPHY
ST_ASGEOJSON
ST_ASGEOJSON(geography_expression)Description
Returns the RFC 7946 compliant GeoJSON
representation of the input GEOGRAPHY.
A BigQuery GEOGRAPHY has spherical
geodesic edges, whereas a GeoJSON Geometry object explicitly has planar edges.
To convert between these two types of edges, BigQuery adds additional
points to the line where necessary so that the resulting sequence of edges
remains within 10 meters of the original edge.
See ST_GEOGFROMGEOJSON to construct a
GEOGRAPHY from GeoJSON.
Return type
STRING
ST_ASTEXT
ST_ASTEXT(geography_expression)Description
Returns the WKT representation of an input
GEOGRAPHY.
See ST_GEOGFROMTEXT to construct a
GEOGRAPHY from WKT.
Return type
STRING
ST_GEOHASH
ST_GEOHASH(geography_expression, maxchars)Description
Returns a GeoHash representation of geography_expression. The
resulting GeoHash will contain at most maxchars characters. Fewer characters
corresponds to lower precision (or, described differently, to a bigger
bounding box).
ST_GeoHash over an empty GEOGRAPHY object returns NULL.
Constraints
- Only
GEOGRAPHYobjects representing single points are supported. - The maximum value of
maxcharsis 20.
Example
Returns a GeoHash of the Seattle Center with 10 characters of precision.
SELECT ST_GEOHASH(ST_GEOGPOINT(-122.35, 47.62), 10) geohash
+--------------+
| geohash |
+--------------+
| c22yzugqw7 |
+--------------+Return type
STRING
ST_ASBINARY
ST_ASBINARY(geography_expression)Description
Returns the WKB representation of an input
GEOGRAPHY.
See ST_GEOGFROMWKB to construct a
GEOGRAPHY from WKB.
Return type
BYTES
ST_BOUNDARY
ST_BOUNDARY(geography_expression)Description
Returns a single GEOGRAPHY that contains the union
of the boundaries of each component in the given input
GEOGRAPHY.
The boundary of each component of a GEOGRAPHY is
defined as follows:
- The boundary of a point is empty.
- The boundary of a linestring consists of the endpoints of the linestring.
- The boundary of a polygon consists of the linestrings that form the polygon shell and each of the polygon's holes.
Return type
GEOGRAPHY
ST_CENTROID
ST_CENTROID(geography_expression)Description
Returns the centroid of the input GEOGRAPHY as a
single point GEOGRAPHY.
The centroid of a GEOGRAPHY is the weighted
average of the centroids of the highest-dimensional components in the
GEOGRAPHY. The centroid for components in each
dimension is defined as follows:
- The centroid of points is the arithmetic mean of the input coordinates.
- The centroid of linestrings is the centroid of all the edges weighted by length. The centroid of each edge is the geodesic midpoint of the edge.
- The centroid of a polygon is its center of mass.
If the input GEOGRAPHY is empty, an empty
GEOGRAPHY is returned.
Constraints
In the unlikely event that the centroid of a
GEOGRAPHY cannot be defined by a single point on
the surface of the Earth, a deterministic but otherwise arbitrary point is
returned. This can only happen if the centroid is exactly at the center of the
Earth, such as the centroid for a pair of antipodal points, and the likelihood
of this happening is vanishingly small.
Return type
GEOGRAPHY
ST_CLOSESTPOINT
ST_CLOSESTPOINT(geography_1, geography_2)ST_CLOSESTPOINT(geography_1, geography_2, use_spheroid)Description
Returns a GEOGRAPHY containing a point on
geography_1 with the smallest possible distance to geography_2. This implies
that the distance between the point returned by ST_CLOSESTPOINT and
geography_2 is less than or equal to the distance between any other point on
geography_1 and geography_2.
If either of the input GEOGRAPHYs is empty,
ST_CLOSESTPOINT returns NULL.
The optional use_spheroid parameter determines how this function measures
distance. If use_spheroid is FALSE, the function measures distance on the
surface of a perfect sphere.
The use_spheroid parameter currently only supports
the value FALSE. The default value of use_spheroid is FALSE.
Return type
GEOGRAPHY
ST_DIFFERENCE
ST_DIFFERENCE(geography_1, geography_2)Description
Returns a GEOGRAPHY that represents the point set
difference of geography_1 and geography_2.
If geometry_1 is completely contained in geometry_2, then ST_DIFFERENCE
returns an empty GEOGRAPHY.
Constraints
The underlying geometric objects that a BigQuery
GEOGRAPHY represents correspond to a closed point
set. Therefore, ST_DIFFERENCE is the closure of the point set difference of
geography_1 and geography_2. This implies that if geography_1 and
geography_2 intersect, then a portion of the boundary of geography_2 could
be in the difference.
Return type
GEOGRAPHY
ST_INTERSECTION
ST_INTERSECTION(geography_1, geography_2)Description
Returns a GEOGRAPHY that represents the point set
intersection of the two input GEOGRAPHYs. Thus,
every point in the intersection appears in both geography_1 and geography_2.
If the two input GEOGRAPHYs are disjoint, that is,
there are no points that appear in both input geometry_1 and geometry_2,
then an empty GEOGRAPHY is returned.
See ST_INTERSECTS, ST_DISJOINT for related predicate functions.
Return type
GEOGRAPHY
ST_SNAPTOGRID
ST_SNAPTOGRID(geography_expression, grid_size)Description
Returns the input GEOGRAPHY, where each vertex has
been snapped to a longitude/latitude grid. The grid size is determined by the
grid_size parameter which is given in degrees.
Constraints
Arbitrary grid sizes are not supported. The grid_size parameter is rounded so
that it is of the form $$10^n$$, where $$-10 < n < 0$$.
Return type
GEOGRAPHY
ST_UNION
ST_UNION(geography_1, geography_2)ST_UNION(array_of_geography)Description
Returns a GEOGRAPHY that represents the point set
union of all input GEOGRAPHYs.
Input can either be two GEOGRAPHYs or an
ARRAY of type GEOGRAPHY.
See ST_UNION_AGG for the aggregate version of ST_UNION.
Return type
GEOGRAPHY
ST_X
ST_X(geography_expression)Description
Returns the longitude in degrees of the single-point input
GEOGRAPHY.
For any input GEOGRAPHY that is not a single point,
including an empty GEOGRAPHY, ST_X returns an
error. Use the SAFE. prefix to obtain NULL.
Return type
FLOAT64
Example
The following example uses ST_X and ST_Y to extract coordinates from
single-point geographies.
WITH points AS
(SELECT ST_GEOGPOINT(i, i + 1) AS p FROM UNNEST([0, 5, 12]) AS i)
SELECT
p,
ST_X(p) as longitude,
ST_Y(p) as latitude
FROM points;
+--------------+-----------+----------+
| p | longitude | latitude |
+--------------+-----------+----------+
| POINT(0 1) | 0.0 | 1.0 |
| POINT(5 6) | 5.0 | 6.0 |
| POINT(12 13) | 12.0 | 13.0 |
+--------------+-----------+----------+ST_Y
ST_Y(geography_expression)Description
Returns the latitude in degrees of the single-point input
GEOGRAPHY.
For any input GEOGRAPHY that is not a single point,
including an empty GEOGRAPHY, ST_Y returns an
error. Use the SAFE. prefix to return NULL instead.
Return type
FLOAT64
Example
See ST_X for example usage.
ST_CONTAINS
ST_CONTAINS(geography_1, geography_2)Description
Returns TRUE if no point of geography_2 is outside geography_1, and
the interiors intersect; returns FALSE otherwise.
NOTE: A GEOGRAPHY does not contain its own
boundary. Compare with ST_COVERS.
Return type
BOOL
Example
The following query tests whether the polygon POLYGON((1 1, 20 1, 10 20, 1 1))
contains each of the three points (0, 0), (1, 1), and (10, 10), which lie
on the exterior, the boundary, and the interior of the polygon respectively.
SELECT
ST_GEOGPOINT(i, i) AS p,
ST_CONTAINS(ST_GEOGFROMTEXT('POLYGON((1 1, 20 1, 10 20, 1 1))'),
ST_GEOGPOINT(i, i)) AS `contains`
FROM UNNEST([0, 1, 10]) AS i;
+--------------+----------+
| p | contains |
+--------------+----------+
| POINT(0 0) | false |
| POINT(1 1) | false |
| POINT(10 10) | true |
+--------------+----------+ST_COVEREDBY
ST_COVEREDBY(geography_1, geography_2)Description
Returns FALSE if geography_1 or geography_2 is empty.
Returns TRUE no points of geography_1 lie in the exterior of geography_2.
Given two GEOGRAPHYs a and b,
ST_COVEREDBY(a, b) returns the same result as
ST_COVERS(b, a). Note the opposite order of arguments.
Return type
BOOL
ST_COVERS
ST_COVERS(geography_1, geography_2)Description
Returns FALSE if geography_1 or geography_2 is empty.
Returns TRUE if no points of geography_2 lie in the exterior of geography_1.
Return type
BOOL
Example
The following query tests whether the polygon POLYGON((1 1, 20 1, 10 20, 1 1))
covers each of the three points (0, 0), (1, 1), and (10, 10), which lie
on the exterior, the boundary, and the interior of the polygon respectively.
SELECT
ST_GEOGPOINT(i, i) AS p,
ST_COVERS(ST_GEOGFROMTEXT('POLYGON((1 1, 20 1, 10 20, 1 1))'),
ST_GEOGPOINT(i, i)) AS `covers`
FROM UNNEST([0, 1, 10]) AS i;
+--------------+--------+
| p | covers |
+--------------+--------+
| POINT(0 0) | false |
| POINT(1 1) | true |
| POINT(10 10) | true |
+--------------+--------+ST_DISJOINT
ST_DISJOINT(geography_1, geography_2)Description
Returns TRUE if the intersection of geography_1 and geography_2 is empty,
that is, no point in geography_1 also appears in geography_2.
ST_DISJOINT is the logical negation of ST_INTERSECTS.
Return type
GEOGRAPHY
ST_DWITHIN
ST_DWITHIN(geography_1, geography_2), distance)ST_DWITHIN(geography_1, geography_2, distance, use_spheroid)Description
Returns TRUE if the distance between at least one point in geography_1 and
one point in geography_2 is less than or equal to the distance given by the
distance argument; otherwise, returns FALSE. If either input
GEOGRAPHY is empty, ST_DWithin returns FALSE. The
given distance is in meters on the surface of the Earth.
The optional use_spheroid parameter determines how this function measures
distance. If use_spheroid is FALSE, the function measures distance on the
surface of a perfect sphere.
The use_spheroid parameter currently only supports
the value FALSE. The default value of use_spheroid is FALSE.
Return type
BOOL
ST_EQUALS
ST_EQUALS(geography_1, geography_2)Description
Returns TRUE if geography_1 and geography_2 represent the same
GEOGRAPHY value. More precisely, this means that
one of the following conditions holds:
ST_COVERS(geography_1, geography_2) = TRUEandST_COVERS(geography_2, geography_1) = TRUE- Both
geography_1andgeography_2are empty.
Therefore, two GEOGRAPHYs may be equal even if the
ordering of points or vertices differ, as long as they still represent the same
geometric structure.
Constraints
ST_EQUALS is not guaranteed to be a transitive function.
Return type
BOOL
ST_INTERSECTS
ST_INTERSECTS(geography_1, geography_2)Description
Returns TRUE if the point set intersection of geography_1 and geography_2
is non-empty. Thus, this function returns TRUE if there is at least one point
that appears in both input GEOGRAPHYs.
If ST_INTERSECTS returns TRUE, it implies that ST_DISJOINT
returns FALSE.
Return type
BOOL
ST_INTERSECTSBOX
ST_INTERSECTSBOX(geography, lng1, lat1, lng2, lat2)Description
Returns TRUE if geography intersects the rectangle between [lng1, lng2]
and [lat1, lat2]. The edges of the rectangle follow constant lines of
longitude and latitude. lng1 and lng2 specify the minimum and maximum
longitude lines that bound the rectangle, and lat1 and lat2 specify the
minimum and maximum constant latitude lines that bound the rectangle.
Specify all longitude and latitude arguments in degrees.
Constraints
The input arguments are subject to the following constraints:
- Latitudes should be in the
[-90, 90]degree range. - Longitudes should be in the
[-180, 180]degree range.
Return type
BOOL
ST_TOUCHES
ST_TOUCHES(geography_1, geography_2)Description
Returns TRUE provided the following two conditions are satisfied:
geography_1intersectsgeography_2.- The interior of
geography_1and the interior ofgeography_2are disjoint.
Return type
BOOL
ST_WITHIN
ST_WITHIN(geography_1, geography_2)Description
Returns TRUE if no point of geography_1 is outside of geography_2 and
the interiors of geography_1 and geography_2 intersect.
Given two geographies a and b, ST_WITHIN(a, b) returns the same result
as ST_CONTAINS(b, a). Note the opposite order of arguments.
Return type
BOOL
ST_ISEMPTY
ST_ISEMPTY(geography_expression)Description
Returns TRUE if the given GEOGRAPHY is empty;
that is, the GEOGRAPHY does not contain any points,
lines, or polygons.
NOTE: A BigQuery empty GEOGRAPHY is not
associated with a particular geometry shape. For example, the results of
expressions ST_GEOGFROMTEXT('POINT EMPTY') and
ST_GEOGFROMTEXT('GEOMETRYCOLLECTION EMPTY') are identical.
Return type
BOOL
ST_ISCOLLECTION
ST_ISCOLLECTION(geography_expression)Description
Returns TRUE if the total number of points, linestrings, and polygons is
greater than one.
An empty GEOGRAPHY is not a collection.
Return type
BOOL
ST_DIMENSION
ST_DIMENSION(geography_expression)Description
Returns the dimension of the highest-dimensional element in the input
GEOGRAPHY.
The dimension of each possible element is as follows:
- The dimension of a point is
0. - The dimension of a linestring is
1. - The dimension of a polygon is
2.
If the input GEOGRAPHY is empty, ST_DIMENSION
returns -1.
Return type
INT64
ST_NUMPOINTS
ST_NUMPOINTS(geography_expression)Description
Returns the number of vertices in the input
GEOGRAPHY. This includes the number of points, the
number of linestring vertices, and the number of polygon vertices.
NOTE: The first and last vertex of a polygon ring are counted as distinct vertices.
Return type
INT64
ST_AREA
ST_AREA(geography_expression)ST_AREA(geography_expression, use_spheroid)Description
Returns the area in square meters covered by the polygons in the input
GEOGRAPHY.
If geography_expression is a point or a line, returns zero. If
geography_expression is a collection, returns the area of the polygons in the
collection; if the collection does not contain polygons, returns zero.
The optional use_spheroid parameter determines how this function measures
distance. If use_spheroid is FALSE, the function measures distance on the
surface of a perfect sphere.
The use_spheroid parameter currently only supports
the value FALSE. The default value of use_spheroid is FALSE.
Return type
FLOAT64
ST_DISTANCE
ST_DISTANCE(geography_1, geography_2)ST_DISTANCE(geography_1, geography_2, use_spheroid)Description
Returns the shortest distance in meters between two non-empty
GEOGRAPHYs.
If either of the input GEOGRAPHYs is empty,
ST_DISTANCE returns NULL.
The optional use_spheroid parameter determines how this function measures
distance. If use_spheroid is FALSE, the function measures distance on the
surface of a perfect sphere.
The use_spheroid parameter currently only supports
the value FALSE. The default value of use_spheroid is FALSE.
Return type
FLOAT64
ST_LENGTH
ST_LENGTH(geography_expression)ST_LENGTH(geography_expression, use_spheroid)Description
Returns the total length in meters of the lines in the input
GEOGRAPHY.
If geography_expression is a point or a polygon, returns zero. If
geography_expression is a collection, returns the length of the lines in the
collection; if the collection does not contain lines, returns zero.
The optional use_spheroid parameter determines how this function measures
distance. If use_spheroid is FALSE, the function measures distance on the
surface of a perfect sphere.
The use_spheroid parameter currently only supports
the value FALSE. The default value of use_spheroid is FALSE.
Return type
FLOAT64
ST_MAXDISTANCE
ST_MAXDISTANCE(geography_1, geography_2)ST_MAXDISTANCE(geography_1, geography_2, use_spheroid)Returns the longest distance in meters between two non-empty
GEOGRAPHYs; that is, the distance between two
vertices where the first vertex is in the first
GEOGRAPHY, and the second vertex is in the second
GEOGRAPHY. If geography_1 and geography_2 are the
same GEOGRAPHY, the function returns the distance
between the two most distant vertices in that
GEOGRAPHY.
If either of the input GEOGRAPHYs is empty,
ST_MAXDISTANCE returns NULL.
The optional use_spheroid parameter determines how this function measures
distance. If use_spheroid is FALSE, the function measures distance on the
surface of a perfect sphere.
The use_spheroid parameter currently only supports
the value FALSE. The default value of use_spheroid is FALSE.
Return type
FLOAT64
ST_PERIMETER
ST_PERIMETER(geography_expression)ST_PERIMETER(geography_expression, use_spheroid)Description
Returns the length in meters of the boundary of the polygons in the input
GEOGRAPHY.
If geography_expression is a point or a line, returns zero. If
geography_expression is a collection, returns the perimeter of the polygons
in the collection; if the collection does not contain polygons, returns zero.
The optional use_spheroid parameter determines how this function measures
distance. If use_spheroid is FALSE, the function measures distance on the
surface of a perfect sphere.
The use_spheroid parameter currently only supports
the value FALSE. The default value of use_spheroid is FALSE.
Return type
FLOAT64
ST_UNION_AGG
ST_UNION_AGG(geography)Description
Returns a GEOGRAPHY that represents the point set
union of all input GEOGRAPHYs.
See ST_UNION for the non-aggregate version of ST_UNION_AGG.
Return type
GEOGRAPHY
ST_CENTROID_AGG
ST_CENTROID_AGG(geography)Description
Computes the centroid of the set of input GEOGRAPHYs
as a single point GEOGRAPHY.
The centroid over the set of input GEOGRAPHYs is
the weighted average of the centroid of each individual
GEOGRAPHY. Only the
GEOGRAPHYs with the highest dimension present in the
input contribute to the centroid of the entire set. For example, if
the input contains both GEOGRAPHYs with lines and
GEOGRAPHYs with only points, ST_CENTROID_AGG
returns the weighted average of the
GEOGRAPHYs with lines, since those have maximal
dimension. In this example, ST_CENTROID_AGG ignores
GEOGRAPHYs with only points when calculating the
aggregate centroid.
See ST_CENTROID for the non-aggregate version of
ST_CENTROID_AGG and the definition of centroid for an individual
GEOGRAPHY value.
Return type
GEOGRAPHY
Example
The following queries compute the aggregate centroid over a set of
GEOGRAPHY values. The input to the first query
contains only points, and therefore each value contribute to the aggregate
centroid. Also notice that ST_CENTROID_AGG is not equivalent to calling
ST_CENTROID on the result of ST_UNION_AGG; duplicates are removed by the
union, unlike ST_CENTROID_AGG. The input to the second query has mixed
dimensions, and only values with the highest dimension in the set, the lines,
affect the aggregate centroid.
SELECT ST_CENTROID_AGG(points) AS st_centroid_agg,
ST_CENTROID(ST_UNION_AGG(points)) AS centroid_of_union
FROM UNNEST([ST_GEOGPOINT(1, 5),
ST_GEOGPOINT(1, 2),
ST_GEOGPOINT(1, -1),
ST_GEOGPOINT(1, -1)]) points;
+---------------------------+-------------------+
| st_centroid_agg | centroid_of_union |
+---------------------------+-------------------+
| POINT(1 1.24961422620969) | POINT(1 2) |
+---------------------------+-------------------+
SELECT ST_CENTROID_AGG(points) AS st_centroid_agg
FROM UNNEST([ST_GEOGPOINT(50, 26),
ST_GEOGPOINT(34, 33.3),
ST_GEOGFROMTEXT('LINESTRING(0 -1, 0 1)')
ST_GEOGFROMTEXT('LINESTRING(0 1, 0 3)')]) points;
+-----------------+
| st_centroid_agg |
+-----------------+
| POINT(0 1) |
+-----------------+https://en.wikipedia.org/wiki/Geohash "GeoHash"
Security functions
BigQuery supports the following security functions.
SESSION_USER
SESSION_USER()Description
Returns the email address of the user that is running the query.
Return Data Type
STRING
Example
SELECT SESSION_USER() as user;
+----------------------+
| user |
+----------------------+
| jdoe@example.com |
+----------------------+UUID functions
BigQuery supports the following universally unique identifier (UUID) functions.
GENERATE_UUID
GENERATE_UUID()Description
Returns a random universally unique identifier (UUID) as a STRING.
The returned STRING consists of 32 hexadecimal
digits in five groups separated by hyphens in the form 8-4-4-4-12. The
hexadecimal digits represent 122 random bits and 6 fixed bits, in compliance
with RFC 4122 section 4.4.
The returned STRING is lowercase.
Return Data Type
STRING
Example
The following query generates a random UUID.
SELECT GENERATE_UUID() AS uuid;The above query generates a result like the following:
+--------------------------------------+
| uuid |
+--------------------------------------+
| 4192bff0-e1e0-43ce-a4db-912808c32493 |
+--------------------------------------+Net functions
NET.IP_FROM_STRING
NET.IP_FROM_STRING(addr_str)Description
Converts an IPv4 or IPv6 address from text (STRING) format to binary (BYTES) format in network byte order.
This function supports the following formats for addr_str:
- IPv4: Dotted-quad format. For example,
10.1.2.3. - IPv6: Colon-separated format. For example,
1234:5678:90ab:cdef:1234:5678:90ab:cdef. For more examples, see the IP Version 6 Addressing Architecture.
This function does not support CIDR notation, such as 10.1.2.3/32.
If this function receives a NULL input, it returns NULL. If the input is
considered invalid, an OUT_OF_RANGE error occurs.
Return Data Type
BYTES
Example
SELECT
addr_str, FORMAT("%T", NET.IP_FROM_STRING(addr_str)) AS ip_from_string
FROM UNNEST([
'48.49.50.51',
'::1',
'3031:3233:3435:3637:3839:4041:4243:4445',
'::ffff:192.0.2.128'
]) AS addr_str;| addr_str | ip_from_string |
|---|---|
| 48.49.50.51 | b"0123" |
| ::1 | b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01" |
| 3031:3233:3435:3637:3839:4041:4243:4445 | b"0123456789@ABCDE" |
| ::ffff:192.0.2.128 | b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\xc0\x00\x02\x80" |
NET.SAFE_IP_FROM_STRING
NET.SAFE_IP_FROM_STRING(addr_str)Description
Similar to NET.IP_FROM_STRING, but returns NULL
instead of throwing an error if the input is invalid.
Return Data Type
BYTES
Example
SELECT
addr_str,
FORMAT("%T", NET.SAFE_IP_FROM_STRING(addr_str)) AS safe_ip_from_string
FROM UNNEST([
'48.49.50.51',
'::1',
'3031:3233:3435:3637:3839:4041:4243:4445',
'::ffff:192.0.2.128',
'48.49.50.51/32',
'48.49.50',
'::wxyz'
]) AS addr_str;| addr_str | safe_ip_from_string |
|---|---|
| 48.49.50.51 | b"0123" |
| ::1 | b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01" |
| 3031:3233:3435:3637:3839:4041:4243:4445 | b"0123456789@ABCDE" |
| ::ffff:192.0.2.128 | b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\xc0\x00\x02\x80" |
| 48.49.50.51/32 | NULL |
| 48.49.50 | NULL |
| ::wxyz | NULL |
NET.IP_TO_STRING
NET.IP_TO_STRING(addr_bin)Description Converts an IPv4 or IPv6 address from binary (BYTES) format in network byte order to text (STRING) format.
If the input is 4 bytes, this function returns an IPv4 address as a STRING. If the input is 16 bytes, it returns an IPv6 address as a STRING.
If this function receives a NULL input, it returns NULL. If the input has
a length different from 4 or 16, an OUT_OF_RANGE error occurs.
Return Data Type
STRING
Example
SELECT FORMAT("%T", x) AS addr_bin, NET.IP_TO_STRING(x) AS ip_to_string
FROM UNNEST([
b"0123",
b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01",
b"0123456789@ABCDE",
b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\xc0\x00\x02\x80"
]) AS x;| addr_bin | ip_to_string |
|---|---|
| b"0123" | 48.49.50.51 |
| b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01" | ::1 |
| b"0123456789@ABCDE" | 3031:3233:3435:3637:3839:4041:4243:4445 |
| b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\xc0\x00\x02\x80" | ::ffff:192.0.2.128 |
NET.IP_NET_MASK
NET.IP_NET_MASK(num_output_bytes, prefix_length)Description
Returns a network mask: a byte sequence with length equal to num_output_bytes,
where the first prefix_length bits are set to 1 and the other bits are set to
0. num_output_bytes and prefix_length are INT64.
This function throws an error if num_output_bytes is not 4 (for IPv4) or 16
(for IPv6). It also throws an error if prefix_length is negative or greater
than 8 * num_output_bytes.
Return Data Type
BYTES
Example
SELECT x, y, FORMAT("%T", NET.IP_NET_MASK(x, y)) AS ip_net_mask
FROM UNNEST([
STRUCT(4 as x, 0 as y),
(4, 20),
(4, 32),
(16, 0),
(16, 1),
(16, 128)
]);| x | y | ip_net_mask |
|---|---|---|
| 4 | 0 | b"\x00\x00\x00\x00" |
| 4 | 20 | b"\xff\xff\xf0\x00" |
| 4 | 32 | b"\xff\xff\xff\xff" |
| 16 | 0 | b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" |
| 16 | 1 | b"\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" |
| 16 | 128 | b"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" |
NET.IP_TRUNC
NET.IP_TRUNC(addr_bin, prefix_length)Description
Takes addr_bin, an IPv4 or IPv6 address in binary (BYTES) format in network
byte order, and returns a subnet address in the same format. The result has the
same length as addr_bin, where the first prefix_length bits are equal to
those in addr_bin and the remaining bits are 0.
This function throws an error if LENGTH(addr_bin) is not 4 or 16, or if
prefix_len is negative or greater than LENGTH(addr_bin) * 8.
Return Data Type
BYTES
Example
SELECT
FORMAT("%T", x) as addr_bin, prefix_length,
FORMAT("%T", NET.IP_TRUNC(x, prefix_length)) AS ip_trunc
FROM UNNEST([
STRUCT(b"\xAA\xBB\xCC\xDD" as x, 0 as prefix_length),
(b"\xAA\xBB\xCC\xDD", 11), (b"\xAA\xBB\xCC\xDD", 12),
(b"\xAA\xBB\xCC\xDD", 24), (b"\xAA\xBB\xCC\xDD", 32),
(b'0123456789@ABCDE', 80)
]);| addr_bin | prefix_length | ip_trunc |
|---|---|---|
| b"\xaa\xbb\xcc\xdd" | 0 | b"\x00\x00\x00\x00" |
| b"\xaa\xbb\xcc\xdd" | 11 | b"\xaa\xa0\x00\x00" |
| b"\xaa\xbb\xcc\xdd" | 12 | b"\xaa\xb0\x00\x00" |
| b"\xaa\xbb\xcc\xdd" | 24 | b"\xaa\xbb\xcc\x00" |
| b"\xaa\xbb\xcc\xdd" | 32 | b"\xaa\xbb\xcc\xdd" |
| b"0123456789@ABCDE" | 80 | b"0123456789\x00\x00\x00\x00\x00\x00" |
NET.IPV4_FROM_INT64
NET.IPV4_FROM_INT64(integer_value)Description
Converts an IPv4 address from integer format to binary (BYTES) format in network
byte order. In the integer input, the least significant bit of the IP address is
stored in the least significant bit of the integer, regardless of host or client
architecture. For example, 1 means 0.0.0.1, and 0x1FF means 0.0.1.255.
This function checks that either all the most significant 32 bits are 0, or all
the most significant 33 bits are 1 (sign-extended from a 32 bit integer).
In other words, the input should be in the range [-0x80000000, 0xFFFFFFFF];
otherwise, this function throws an error.
This function does not support IPv6.
Return Data Type
BYTES
Example
SELECT x, x_hex, FORMAT("%T", NET.IPV4_FROM_INT64(x)) AS ipv4_from_int64
FROM (
SELECT CAST(x_hex AS INT64) x, x_hex
FROM UNNEST(["0x0", "0xABCDEF", "0xFFFFFFFF", "-0x1", "-0x2"]) AS x_hex
);| x | x_hex | ipv4_from_int64 |
|---|---|---|
| 0 | 0x0 | b"\x00\x00\x00\x00" |
| 11259375 | 0xABCDEF | b"\x00\xab\xcd\xef" |
| 4294967295 | 0xFFFFFFFF | b"\xff\xff\xff\xff" |
| -1 | -0x1 | b"\xff\xff\xff\xff" |
| -2 | -0x2 | b"\xff\xff\xff\xfe" |
NET.IPV4_TO_INT64
NET.IPV4_TO_INT64(addr_bin)Description
Converts an IPv4 address from binary (BYTES) format in network byte order to
integer format. In the integer output, the least significant bit of the IP
address is stored in the least significant bit of the integer, regardless of
host or client architecture. For example, 1 means 0.0.0.1, and 0x1FF means
0.0.1.255. The output is in the range [0, 0xFFFFFFFF].
If the input length is not 4, this function throws an error.
This function does not support IPv6.
Return Data Type
INT64
Example
SELECT
FORMAT("%T", x) AS addr_bin,
FORMAT("0x%X", NET.IPV4_TO_INT64(x)) AS ipv4_to_int64
FROM
UNNEST([b"\x00\x00\x00\x00", b"\x00\xab\xcd\xef", b"\xff\xff\xff\xff"]) AS x;| addr_bin | ipv4_to_int64 |
|---|---|
| b"\x00\x00\x00\x00" | 0x0 |
| b"\x00\xab\xcd\xef" | 0xABCDEF |
| b"\xff\xff\xff\xff" | 0xFFFFFFFF |
NET.HOST
NET.HOST(url)Description
Takes a URL as a STRING and returns the host as a STRING. For best results, URL values should comply with the format as defined by RFC 3986. If the URL value does not comply with RFC 3986 formatting, this function makes a best effort to parse the input and return a relevant result. If the function cannot parse the input, it returns NULL.
Note: The function does not perform any normalization.
Return Data Type
STRING
Example
SELECT
FORMAT("%T", input) AS input,
description,
FORMAT("%T", NET.HOST(input)) AS host,
FORMAT("%T", NET.PUBLIC_SUFFIX(input)) AS suffix,
FORMAT("%T", NET.REG_DOMAIN(input)) AS domain
FROM (
SELECT "" AS input, "invalid input" AS description
UNION ALL SELECT "http://abc.xyz", "standard URL"
UNION ALL SELECT "//user:password@a.b:80/path?query",
"standard URL with relative scheme, port, path and query, but no public suffix"
UNION ALL SELECT "https://[::1]:80", "standard URL with IPv6 host"
UNION ALL SELECT "http://例子.卷筒纸.中国", "standard URL with internationalized domain name"
UNION ALL SELECT " www.Example.Co.UK ",
"non-standard URL with spaces, upper case letters, and without scheme"
UNION ALL SELECT "mailto:?to=&subject=&body=", "URI rather than URL--unsupported"
);| input | description | host | suffix | domain |
|---|---|---|---|---|
| "" | invalid input | NULL | NULL | NULL |
| "http://abc.xyz" | standard URL | "abc.xyz" | "xyz" | "abc.xyz" |
| "//user:password@a.b:80/path?query" | standard URL with relative scheme, port, path and query, but no public suffix | "a.b" | NULL | NULL |
| "https://[::1]:80" | standard URL with IPv6 host | "[::1]" | NULL | NULL |
| "http://例子.卷筒纸.中国" | standard URL with internationalized domain name | "例子.卷筒纸.中国" | "中国" | "卷筒纸.中国" |
| " www.Example.Co.UK " | non-standard URL with spaces, upper case letters, and without scheme | "www.Example.Co.UK" | "Co.UK" | "Example.Co.UK" |
| "mailto:?to=&subject=&body=" | URI rather than URL--unsupported | "mailto" | NULL | NULL |
NET.PUBLIC_SUFFIX
NET.PUBLIC_SUFFIX(url)Description
Takes a URL as a STRING and returns the public suffix (such as com, org,
or net) as a STRING. A public suffix is an ICANN domain registered at
publicsuffix.org. For best results, URL values
should comply with the format as defined by
RFC 3986. If the URL value does not comply
with RFC 3986 formatting, this function makes a best effort to parse the input
and return a relevant result.
This function returns NULL if any of the following is true:
- It cannot parse the host from the input;
- The parsed host contains adjacent dots in the middle (not leading or trailing);
- The parsed host does not contain any public suffix.
Before looking up the public suffix, this function temporarily normalizes the host by converting upper case English letters to lower case and encoding all non-ASCII characters with Punycode. The function then returns the public suffix as part of the original host instead of the normalized host.
Note: The function does not perform Unicode normalization.
Note: The public suffix data at publicsuffix.org also contains private domains. This function ignores the private domains.
Note: The public suffix data may change over time. Consequently, input that produces a NULL result now may produce a non-NULL value in the future.
Return Data Type
STRING
Example
SELECT
FORMAT("%T", input) AS input,
description,
FORMAT("%T", NET.HOST(input)) AS host,
FORMAT("%T", NET.PUBLIC_SUFFIX(input)) AS suffix,
FORMAT("%T", NET.REG_DOMAIN(input)) AS domain
FROM (
SELECT "" AS input, "invalid input" AS description
UNION ALL SELECT "http://abc.xyz", "standard URL"
UNION ALL SELECT "//user:password@a.b:80/path?query",
"standard URL with relative scheme, port, path and query, but no public suffix"
UNION ALL SELECT "https://[::1]:80", "standard URL with IPv6 host"
UNION ALL SELECT "http://例子.卷筒纸.中国", "standard URL with internationalized domain name"
UNION ALL SELECT " www.Example.Co.UK ",
"non-standard URL with spaces, upper case letters, and without scheme"
UNION ALL SELECT "mailto:?to=&subject=&body=", "URI rather than URL--unsupported"
);| input | description | host | suffix | domain |
|---|---|---|---|---|
| "" | invalid input | NULL | NULL | NULL |
| "http://abc.xyz" | standard URL | "abc.xyz" | "xyz" | "abc.xyz" |
| "//user:password@a.b:80/path?query" | standard URL with relative scheme, port, path and query, but no public suffix | "a.b" | NULL | NULL |
| "https://[::1]:80" | standard URL with IPv6 host | "[::1]" | NULL | NULL |
| "http://例子.卷筒纸.中国" | standard URL with internationalized domain name | "例子.卷筒纸.中国" | "中国" | "卷筒纸.中国" |
| " www.Example.Co.UK " | non-standard URL with spaces, upper case letters, and without scheme | "www.Example.Co.UK" | "Co.UK" | "Example.Co.UK |
| "mailto:?to=&subject=&body=" | URI rather than URL--unsupported | "mailto" | NULL | NULL |
NET.REG_DOMAIN
NET.REG_DOMAIN(url)Description
Takes a URL as a STRING and returns the registered or registerable domain (the public suffix plus one preceding label), as a STRING. For best results, URL values should comply with the format as defined by RFC 3986. If the URL value does not comply with RFC 3986 formatting, this function makes a best effort to parse the input and return a relevant result.
This function returns NULL if any of the following is true:
- It cannot parse the host from the input;
- The parsed host contains adjacent dots in the middle (not leading or trailing);
- The parsed host does not contain any public suffix;
- The parsed host contains only a public suffix without any preceding label.
Before looking up the public suffix, this function temporarily normalizes the host by converting upper case English letters to lowercase and encoding all non-ASCII characters with Punycode. The function then returns the registered or registerable domain as part of the original host instead of the normalized host.
Note: The function does not perform Unicode normalization.
Note: The public suffix data at publicsuffix.org also contains private domains. This function does not treat a private domain as a public suffix. For example, if "us.com" is a private domain in the public suffix data, NET.REG_DOMAIN("foo.us.com") returns "us.com" (the public suffix "com" plus the preceding label "us") rather than "foo.us.com" (the private domain "us.com" plus the preceding label "foo").
Note: The public suffix data may change over time. Consequently, input that produces a NULL result now may produce a non-NULL value in the future.
Return Data Type
STRING
Example
SELECT
FORMAT("%T", input) AS input,
description,
FORMAT("%T", NET.HOST(input)) AS host,
FORMAT("%T", NET.PUBLIC_SUFFIX(input)) AS suffix,
FORMAT("%T", NET.REG_DOMAIN(input)) AS domain
FROM (
SELECT "" AS input, "invalid input" AS description
UNION ALL SELECT "http://abc.xyz", "standard URL"
UNION ALL SELECT "//user:password@a.b:80/path?query",
"standard URL with relative scheme, port, path and query, but no public suffix"
UNION ALL SELECT "https://[::1]:80", "standard URL with IPv6 host"
UNION ALL SELECT "http://例子.卷筒纸.中国", "standard URL with internationalized domain name"
UNION ALL SELECT " www.Example.Co.UK ",
"non-standard URL with spaces, upper case letters, and without scheme"
UNION ALL SELECT "mailto:?to=&subject=&body=", "URI rather than URL--unsupported"
);| input | description | host | suffix | domain |
|---|---|---|---|---|
| "" | invalid input | NULL | NULL | NULL |
| "http://abc.xyz" | standard URL | "abc.xyz" | "xyz" | "abc.xyz" |
| "//user:password@a.b:80/path?query" | standard URL with relative scheme, port, path and query, but no public suffix | "a.b" | NULL | NULL |
| "https://[::1]:80" | standard URL with IPv6 host | "[::1]" | NULL | NULL |
| "http://例子.卷筒纸.中国" | standard URL with internationalized domain name | "例子.卷筒纸.中国" | "中国" | "卷筒纸.中国" |
| " www.Example.Co.UK " | non-standard URL with spaces, upper case letters, and without scheme | "www.Example.Co.UK" | "Co.UK" | "Example.Co.UK" |
| "mailto:?to=&subject=&body=" | URI rather than URL--unsupported | "mailto" | NULL | NULL |
Operators
Operators are represented by special characters or keywords; they do not use function call syntax. An operator manipulates any number of data inputs, also called operands, and returns a result.
Common conventions:
- Unless otherwise specified, all operators return
NULLwhen one of the operands isNULL. - All operators will throw an error if the computation result overflows.
- For all floating point operations,
+/-infandNaNmay only be returned if one of the operands is+/-inforNaN. In other cases, an error is returned.
The following table lists all BigQuery operators from highest to lowest precedence, i.e. the order in which they will be evaluated within a statement.
| Order of Precedence | Operator | Input Data Types | Name | Operator Arity |
|---|---|---|---|---|
| 1 | . | STRUCT |
Member field access operator | Binary |
| [ ] | ARRAY | Array position. Must be used with OFFSET or ORDINAL—see ARRAY Functions. | Binary | |
| 2 | - | All numeric types | Unary minus | Unary |
| ~ | Integer or BYTES | Bitwise not | Unary | |
| 3 | * | All numeric types | Multiplication | Binary |
| / | All numeric types | Division | Binary | |
| 4 | + | All numeric types | Addition | Binary |
| - | All numeric types | Subtraction | Binary | |
| 5 | << | Integer or BYTES | Bitwise left-shift | Binary |
| >> | Integer or BYTES | Bitwise right-shift | Binary | |
| 6 | & | Integer or BYTES | Bitwise and | Binary |
| 7 | ^ | Integer or BYTES | Bitwise xor | Binary |
| 8 | | | Integer or BYTES | Bitwise or | Binary |
| 9 (Comparison Operators) | = | Any comparable type. See Data Types for a complete list. | Equal | Binary |
| < | Any comparable type. See Data Types for a complete list. | Less than | Binary | |
| > | Any comparable type. See Data Types for a complete list. | Greater than | Binary | |
| <= | Any comparable type. See Data Types for a complete list. | Less than or equal to | Binary | |
| >= | Any comparable type. See Data Types for a complete list. | Greater than or equal to | Binary | |
| !=, <> | Any comparable type. See Data Types for a complete list. | Not equal | Binary | |
| [NOT] LIKE | STRING and byte | Value does [not] match the pattern specified | Binary | |
| [NOT] BETWEEN | Any comparable types. See Data Types for list. | Value is [not] within the range specified | Binary | |
| [NOT] IN | Any comparable types. See Data Types for list. | Value is [not] in the set of values specified | Binary | |
IS [NOT] NULL |
All | Value is [not] NULL |
Unary | |
| IS [NOT] TRUE | BOOL | Value is [not] TRUE. | Unary | |
| IS [NOT] FALSE | BOOL | Value is [not] FALSE. | Unary | |
| 10 | NOT | BOOL | Logical NOT | Unary |
| 11 | AND | BOOL | Logical AND | Binary |
| 12 | OR | BOOL | Logical OR | Binary |
Operators with the same precedence are left associative. This means that those operators are grouped together starting from the left and moving right. For example, the expression:
x AND y AND z
is interpreted as
( ( x AND y ) AND z )
The expression:
x * y / zis interpreted as:
( ( x * y ) / z )All comparison operators have the same priority and are grouped using left associativity. However, comparison operators are not associative. As a result, it is recommended that you use parentheses to improve readability and ensure expressions are resolved as desired. For example:
(x < y) IS FALSE
is recommended over:
x < y IS FALSE
Element access operators
| Operator | Syntax | Input Data Types | Result Data Type | Description |
|---|---|---|---|---|
| . | expression.fieldname1... | STRUCT |
Type T stored in fieldname1 | Dot operator. Can be used to access nested fields, e.g.expression.fieldname1.fieldname2... |
| [ ] | array_expression [position_keyword (int_expression ) ] | See ARRAY Functions. | Type T stored in ARRAY | position_keyword is either OFFSET or ORDINAL. See ARRAY Functions for the two functions that use this operator. |
Arithmetic operators
All arithmetic operators accept input of numeric type T, and the result type has type T unless otherwise indicated in the description below:
| Name | Syntax |
|---|---|
| Addition | X + Y |
| Subtraction | X - Y |
| Multiplication | X * Y |
| Division | X / Y |
| Unary Minus | - X |
NOTE: Divide by zero operations return an error. To return a different result, consider the IEEE_DIVIDE or SAFE_DIVIDE functions.
Result types for Addition and Multiplication:
| INT64 | NUMERIC | FLOAT64 | |
|---|---|---|---|
| INT64 | INT64 | NUMERIC | FLOAT64 |
| NUMERIC | NUMERIC | NUMERIC | FLOAT64 |
| FLOAT64 | FLOAT64 | FLOAT64 | FLOAT64 |
Result types for Subtraction:
| INT64 | NUMERIC | FLOAT64 | |
|---|---|---|---|
| INT64 | INT64 | NUMERIC | FLOAT64 |
| NUMERIC | NUMERIC | NUMERIC | FLOAT64 |
| FLOAT64 | FLOAT64 | FLOAT64 | FLOAT64 |
Result types for Division:
| INT64 | NUMERIC | FLOAT64 | |
|---|---|---|---|
| INT64 | FLOAT64 | NUMERIC | FLOAT64 |
| NUMERIC | NUMERIC | NUMERIC | FLOAT64 |
| FLOAT64 | FLOAT64 | FLOAT64 | FLOAT64 |
Result types for Unary Minus:
| Input Data Type | Result Data Type |
|---|---|
| INT64 | INT64 |
| NUMERIC | NUMERIC |
| FLOAT64 | FLOAT64 |
Bitwise operators
All bitwise operators return the same type and the same length as the first operand.
| Name | Syntax | Input Data Type | Description |
|---|---|---|---|
| Bitwise not | ~ X | Integer or BYTES | Performs logical negation on each bit, forming the ones' complement of the given binary value. |
| Bitwise or | X | Y | X: Integer or BYTES
Y: Same type as X |
Takes two bit patterns of equal length and performs the logical inclusive OR operation on each pair of the corresponding bits. This operator throws an error if X and Y are BYTES of different lengths. |
| Bitwise xor | X ^ Y | X: Integer or BYTES
Y: Same type as X |
Takes two bit patterns of equal length and performs the logical exclusive OR operation on each pair of the corresponding bits. This operator throws an error if X and Y are BYTES of different lengths. |
| Bitwise and | X & Y | X: Integer or BYTES
Y: Same type as X |
Takes two bit patterns of equal length and performs the logical AND operation on each pair of the corresponding bits. This operator throws an error if X and Y are BYTES of different lengths. |
| Left shift | X << Y | X: Integer or BYTES
Y: INT64 |
Shifts the first operand X to the left. This operator returns 0 or a byte sequence of b'\x00' if the second operand Y is greater than or equal to the bit length of the first operand X (for example, 64 if X has the type INT64). This operator throws an error if Y is negative. |
| Right shift | X >> Y | X: Integer or BYTES
Y: INT64 |
Shifts the first operand X to the right. This operator does not do sign bit extension with a signed type (i.e. it fills vacant bits on the left with 0). This operator returns 0 or a byte sequence of b'\x00' if the second operand Y is greater than or equal to the bit length of the first operand X (for example, 64 if X has the type INT64). This operator throws an error if Y is negative. |
Logical operators
All logical operators allow only BOOL input.
| Name | Syntax | Description |
|---|---|---|
| Logical NOT | NOT X | Returns FALSE if input is TRUE. Returns TRUE if input is FALSE. Returns NULL
otherwise. |
| Logical AND | X AND Y | Returns FALSE if at least one input is FALSE. Returns TRUE if both X and Y
are TRUE. Returns NULL otherwise. |
| Logical OR | X OR Y | Returns FALSE if both X and Y are FALSE. Returns TRUE if at least one input
is TRUE. Returns NULL otherwise. |
Comparison operators
Comparisons always return BOOL. Comparisons generally require both operands to be of the same type. If operands are of different types, and if BigQuery can convert the values of those types to a common type without loss of precision, BigQuery will generally coerce them to that common type for the comparison; BigQuery will generally coerce literals to the type of non-literals, where present. Comparable data types are defined in Data Types.
STRUCTs support only 4 comparison operators: equal (=), not equal (!= and <>), and IN.
The following rules apply when comparing these data types:
- FLOAT64
: All comparisons with NaN return FALSE,
except for
!=and<>, which return TRUE. - BOOL: FALSE is less than TRUE.
- STRING: Strings are compared codepoint-by-codepoint, which means that canonically equivalent strings are only guaranteed to compare as equal if they have been normalized first.
NULL: The convention holds here: any operation with aNULLinput returnsNULL.
| Name | Syntax | Description |
|---|---|---|
| Less Than | X < Y | Returns TRUE if X is less than Y. |
| Less Than or Equal To | X <= Y | Returns TRUE if X is less than or equal to Y. |
| Greater Than | X > Y | Returns TRUE if X is greater than Y. |
| Greater Than or Equal To | X >= Y | Returns TRUE if X is greater than or equal to Y. |
| Equal | X = Y | Returns TRUE if X is equal to Y. |
| Not Equal | X != Y X <> Y |
Returns TRUE if X is not equal to Y. |
| BETWEEN | X [NOT] BETWEEN Y AND Z | Returns TRUE if X is [not] within the range specified. The result of "X BETWEEN Y AND Z" is equivalent to "Y <= X AND X <= Z" but X is evaluated only once in the former. |
| LIKE | X [NOT] LIKE Y | Checks if the STRING in the first operand X
matches a pattern specified by the second operand Y. Expressions can contain
these characters:
|
| IN | Multiple - see below | Returns FALSE if the right operand is empty. Returns NULL if the left
operand is NULL. Returns TRUE or NULL, never FALSE, if the right operand
contains NULL. Arguments on either side of IN are general expressions. Neither
operand is required to be a literal, although using a literal on the right is
most common. X is evaluated only once. |
When testing values that have a STRUCT data type for
equality, it's possible that one or more fields are NULL. In such cases:
- If all non-NULL field values are equal, the comparison returns NULL.
- If any non-NULL field values are not equal, the comparison returns false.
The following table demonstrates how STRUCT data
types are compared when they have fields that are NULL valued.
| Struct1 | Struct2 | Struct1 = Struct2 |
|---|---|---|
STRUCT(1, NULL) |
STRUCT(1, NULL) |
NULL |
STRUCT(1, NULL) |
STRUCT(2, NULL) |
FALSE |
STRUCT(1,2) |
STRUCT(1, NULL) |
NULLIN operators
The IN operator supports the following syntaxes:
x [NOT] IN (y, z, ... ) # Requires at least one element
x [NOT] IN (<subquery>)
x [NOT] IN UNNEST(<array expression>) # analysis error if the expression
# does not return an ARRAY type.Arguments on either side of the IN operator are general expressions.
It is common to use literals on the right side expression; however, this is not
required.
The semantics of:
x IN (y, z, ...)are defined as equivalent to:
(x = y) OR (x = z) OR ...and the subquery and array forms are defined similarly.
x NOT IN ...is equivalent to:
NOT(x IN ...)The UNNEST form treats an array scan like UNNEST in the
FROM clause:
x [NOT] IN UNNEST(<array expression>)This form is often used with ARRAY parameters. For example:
x IN UNNEST(@array_parameter)Note: A NULL ARRAY will be treated equivalently to an empty ARRAY.
See the Arrays topic for more information on how to use this syntax.
When using the IN operator, the following semantics apply:
INwith an empty right side expression is always FALSEINwith aNULLleft side expression and a non-empty right side expression is alwaysNULLINwith aNULLin theIN-list can only return TRUE orNULL, never FALSENULL IN (NULL)returnsNULLIN UNNEST(<NULL array>)returns FALSE (notNULL)
IN can be used with multi-part keys by using the struct constructor syntax.
For example:
(Key1, Key2) IN ( (12,34), (56,78) )
(Key1, Key2) IN ( SELECT (table.a, table.b) FROM table )See the Struct Type section of the Data Types topic for more information on this syntax.
IS operators
IS operators return TRUE or FALSE for the condition they are testing. They never
return NULL, even for NULL inputs, unlike the IS_INF and IS_NAN functions
defined in Mathematical Functions. If NOT is present,
the output BOOL value is inverted.
| Function Syntax | Input Data Type | Result Data Type | Description |
|---|---|---|---|
X IS [NOT] NULL |
Any value type | BOOL | Returns TRUE if the operand X evaluates to NULL, and returns FALSE
otherwise. |
X IS [NOT] TRUE |
BOOL | BOOL | Returns TRUE if the BOOL operand evaluates to TRUE. Returns FALSE otherwise. |
X IS [NOT] FALSE |
BOOL | BOOL | Returns TRUE if the BOOL operand evaluates to FALSE. Returns FALSE otherwise. |
Conditional expressions
Conditional expressions impose constraints on the evaluation order of their inputs. In essence, they are evaluated left to right, with short-circuiting, and only evaluate the output value that was chosen. In contrast, all inputs to regular functions are evaluated before calling the function. Short-circuiting in conditional expressions can be exploited for error handling or performance tuning.
Expression subqueries
There are four types of expression subqueries, i.e. subqueries that are used as
expressions. Expression subqueries return NULL or a single value, as opposed to
a column or table, and must be surrounded by parentheses. For a fuller
discussion of subqueries, see
Subqueries.
| Type of Subquery | Result Data Type | Description |
|---|---|---|
| Scalar | Any type T | A subquery in parentheses inside an expression (e.g. in the
SELECT list or WHERE clause) is interpreted as a
scalar subquery. The SELECT list in a scalar subquery must have
exactly one field. If the subquery returns exactly one row, that single value is
the scalar subquery result. If the subquery returns zero rows, the scalar
subquery value is NULL. If the subquery returns more than one row, the query
fails with a runtime error. When the subquery is written with SELECT AS
STRUCT , it can include multiple
columns, and the returned value is the constructed STRUCT. Selecting
multiple columns without using SELECT AS is an error. |
| ARRAY | ARRAY | Can use SELECT AS STRUCT to
build arrays of structs, and conversely, selecting multiple columns
without using SELECT AS is an error. Returns an empty ARRAY if the
subquery returns zero rows. Never returns a NULL ARRAY. |
| IN | BOOL | Occurs in an expression following the IN operator. The subquery must produce
a single column whose type is equality-compatible with the expression on the
left side of the IN operator. Returns FALSE if the subquery returns zero rows.
x IN () is equivalent to x IN (value, value, ...)
See the IN operator in
Comparison Operators
for full semantics. |
| EXISTS | BOOL | Returns TRUE if the subquery produced one or more rows. Returns FALSE if the
subquery produces zero rows. Never returns NULL. Unlike all other expression
subqueries, there are no rules about the column list. Any number of columns may
be selected and it will not affect the query result. |
Examples
The following examples of expression subqueries assume that t.int_array has
type ARRAY<INT64>.
| Type | Subquery | Result Data Type | Notes |
|---|---|---|---|
| Scalar | (SELECT COUNT(*) FROM t.int_array) |
INT64 | |
(SELECT DISTINCT i FROM t.int_array i) |
INT64, possibly runtime error | ||
(SELECT i FROM t.int_array i WHERE i=5) |
INT64, possibly runtime error | ||
(SELECT ARRAY_AGG(i) FROM t.int_array i) |
ARRAY | Uses the ARRAY_AGG aggregation function to return an ARRAY. | |
(SELECT 'xxx' a) |
STRING | ||
(SELECT 'xxx' a, 123 b) |
Error | Returns an error because there is more than one column | |
(SELECT AS STRUCT 'xxx' a, 123 b) |
STRUCT | ||
(SELECT AS STRUCT 'xxx' a) |
STRUCT | ||
| ARRAY | ARRAY(SELECT COUNT(*) FROM t.int_array) |
ARRAY of size 1 | |
ARRAY(SELECT x FROM t) |
ARRAY | ||
ARRAY(SELECT 5 a, COUNT(*) b FROM t.int_array) |
Error | Returns an error because there is more than one column | |
ARRAY(SELECT AS STRUCT 5 a, COUNT(*) b FROM t.int_array) |
ARRAY | ||
ARRAY(SELECT AS STRUCT i FROM t.int_array i) |
ARRAY | Makes an ARRAY of one-field STRUCTs | |
ARRAY(SELECT AS STRUCT 1 x, 2, 3 x) |
ARRAY | Returns an ARRAY of STRUCTs with anonymous or duplicate fields. | |
ARRAY(SELECT AS TypeName SUM(x) a, SUM(y) b, SUM(z) c from t) |
array<TypeName> | Selecting into a named type. Assume TypeName is a STRUCT type with fields a,b,c. | |
| STRUCT | (SELECT AS STRUCT 1 x, 2, 3 x) |
STRUCT | Constructs a STRUCT with anonymous or duplicate fields. |
| EXISTS | EXISTS(SELECT x,y,z FROM table WHERE y=z) |
BOOL | |
NOT EXISTS(SELECT x,y,z FROM table WHERE y=z) |
BOOL | ||
| IN | x IN (SELECT y FROM table WHERE z) |
BOOL | |
x NOT IN (SELECT y FROM table WHERE z) |
BOOL |
Debugging functions
BigQuery supports the following debugging functions.
ERROR
ERROR(error_message)Description
Returns an error. The error_message argument is a STRING.
BigQuery treats ERROR in the same way as any expression that may
result in an error: there is no special guarantee of evaluation order.
Return Data Type
BigQuery infers the return type in context.
Examples
In the following example, the query returns an error message if the value of the row does not match one of two defined values.
SELECT
CASE
WHEN value = 'foo' THEN 'Value is foo.'
WHEN value = 'bar' THEN 'Value is bar.'
ELSE ERROR(concat('Found unexpected value: ', value))
END AS new_value
FROM (
SELECT 'foo' AS value UNION ALL
SELECT 'bar' AS value UNION ALL
SELECT 'baz' AS value);
Found unexpected value: bazIn the following example, BigQuery may evaluate the ERROR function
before or after the x > 0WHERE clause conditions and
there are no special guarantees for the ERROR function.
SELECT *
FROM (SELECT -1 AS x)
WHERE x > 0 AND ERROR('Example error');In the next example, the WHERE clause evaluates an IF condition, which
ensures that BigQuery only evaluates the ERROR function if the
condition fails.
SELECT *
FROM (SELECT -1 AS x)
WHERE IF(x > 0, true, ERROR(FORMAT('Error: x must be positive but is %t', x)));'
Error: x must be positive but is -1
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