GoogleSQL for Spanner supports 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 position. 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.
Function list
Name | Summary |
---|---|
ARRAY_TO_STRING
|
Produces a concatenation of the elements in an array as a
STRING value.
For more information, see Array functions. |
BYTE_LENGTH
|
Gets the number of BYTES in a STRING or
BYTES value.
|
CHAR_LENGTH
|
Gets the number of characters in a STRING value.
|
CHARACTER_LENGTH
|
Synonym for CHAR_LENGTH .
|
CODE_POINTS_TO_BYTES
|
Converts an array of extended ASCII code points to a
BYTES value.
|
CODE_POINTS_TO_STRING
|
Converts an array of extended ASCII code points to a
STRING value.
|
CONCAT
|
Concatenates one or more STRING or BYTES
values into a single result.
|
ENDS_WITH
|
Checks if a STRING or BYTES value is the suffix
of another value.
|
FORMAT
|
Formats data and produces the results as a STRING value.
|
FROM_BASE32
|
Converts a base32-encoded STRING value into a
BYTES value.
|
FROM_BASE64
|
Converts a base64-encoded STRING value into a
BYTES value.
|
FROM_HEX
|
Converts a hexadecimal-encoded STRING value into a
BYTES value.
|
LAX_STRING
|
Attempts to convert a JSON value to a SQL STRING value.
For more information, see JSON functions. |
LENGTH
|
Gets the length of a STRING or BYTES value.
|
LOWER
|
Formats alphabetic characters in a STRING value as
lowercase.
Formats ASCII characters in a BYTES value as
lowercase.
|
LPAD
|
Prepends a STRING or BYTES value with a pattern.
|
LTRIM
|
Identical to the TRIM function, but only removes leading
characters.
|
NORMALIZE
|
Case-sensitively normalizes the characters in a STRING value.
|
NORMALIZE_AND_CASEFOLD
|
Case-insensitively normalizes the characters in a STRING value.
|
REGEXP_CONTAINS
|
Checks if a value is a partial match for a regular expression. |
REGEXP_EXTRACT
|
Produces a substring that matches a regular expression. |
REGEXP_EXTRACT_ALL
|
Produces an array of all substrings that match a regular expression. |
REGEXP_REPLACE
|
Produces a STRING value where all substrings that match a
regular expression are replaced with a specified value.
|
REPEAT
|
Produces a STRING or BYTES value that consists of
an original value, repeated.
|
REPLACE
|
Replaces all occurrences of a pattern with another pattern in a
STRING or BYTES value.
|
REVERSE
|
Reverses a STRING or BYTES value.
|
RPAD
|
Appends a STRING or BYTES value with a pattern.
|
RTRIM
|
Identical to the TRIM function, but only removes trailing
characters.
|
SAFE_CONVERT_BYTES_TO_STRING
|
Converts a BYTES value to a STRING value and
replace any invalid UTF-8 characters with the Unicode replacement character,
U+FFFD .
|
SOUNDEX
|
Gets the Soundex codes for words in a STRING value.
|
SPLIT
|
Splits a STRING or BYTES value, using a delimiter.
|
STARTS_WITH
|
Checks if a STRING or BYTES value is a
prefix of another value.
|
STRING (JSON)
|
Converts a JSON string to a SQL STRING value.
For more information, see JSON functions. |
STRING_ARRAY
|
Converts a JSON array of strings to a SQL ARRAY<STRING>
value.
For more information, see JSON functions. |
STRING (Timestamp)
|
Converts a TIMESTAMP value to a STRING value.
For more information, see Timestamp functions. |
STRING_AGG
|
Concatenates non-NULL STRING or
BYTES values.
For more information, see Aggregate functions. |
STRPOS
|
Finds the position of the first occurrence of a subvalue inside another value. |
SUBSTR
|
Gets a portion of a STRING or BYTES value.
|
TO_BASE32
|
Converts a BYTES value to a
base32-encoded STRING value.
|
TO_BASE64
|
Converts a BYTES value to a
base64-encoded STRING value.
|
TO_CODE_POINTS
|
Converts a STRING or BYTES value into an array of
extended ASCII code points.
|
TO_HEX
|
Converts a BYTES value to a
hexadecimal STRING value.
|
TRIM
|
Removes the specified leading and trailing Unicode code points or bytes
from a STRING or BYTES value.
|
UPPER
|
Formats alphabetic characters in a STRING value as
uppercase.
Formats ASCII characters in a BYTES value as
uppercase.
|
BYTE_LENGTH
BYTE_LENGTH(value)
Description
Gets the number of BYTES
in a STRING
or BYTES
value,
regardless of whether the value is a STRING
or BYTES
type.
Return type
INT64
Examples
SELECT BYTE_LENGTH('абвгд') AS string_example;
/*----------------*
| string_example |
+----------------+
| 10 |
*----------------*/
SELECT BYTE_LENGTH(b'абвгд') AS bytes_example;
/*----------------*
| bytes_example |
+----------------+
| 10 |
*----------------*/
CHAR_LENGTH
CHAR_LENGTH(value)
Description
Gets the number of characters in a STRING
value.
Return type
INT64
Examples
SELECT CHAR_LENGTH('абвгд') AS char_length;
/*-------------*
| char_length |
+-------------+
| 5 |
*------------ */
CHARACTER_LENGTH
CHARACTER_LENGTH(value)
Description
Synonym for CHAR_LENGTH.
Return type
INT64
Examples
SELECT
'абвгд' AS characters,
CHARACTER_LENGTH('абвгд') AS char_length_example
/*------------+---------------------*
| characters | char_length_example |
+------------+---------------------+
| абвгд | 5 |
*------------+---------------------*/
CODE_POINTS_TO_BYTES
CODE_POINTS_TO_BYTES(ascii_code_points)
Description
Takes an array of extended ASCII
code points
as ARRAY<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;
-- Note that the result of CODE_POINTS_TO_BYTES is of type BYTES, displayed as a base64-encoded string.
-- In BYTES format, b'AbCd' is the result.
/*----------*
| bytes |
+----------+
| QWJDZA== |
*----------*/
The following example uses a rotate-by-13 places (ROT13) algorithm to encode a string.
SELECT CODE_POINTS_TO_BYTES(ARRAY(
(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(ARRAY[code]) AS chr
FROM UNNEST(TO_CODE_POINTS(input)) AS code WITH OFFSET
ORDER BY OFFSET)
))) AS encoded_string
FROM UNNEST(ARRAY['Test String!']) AS input;
-- Note that the result of CODE_POINTS_TO_BYTES is of type BYTES, displayed as a base64-encoded string.
-- In BYTES format, b'Grfg Fgevat!' is the result.
/*------------------*
| encoded_string |
+------------------+
| R3JmZyBGZ2V2YXQh |
*------------------*/
CODE_POINTS_TO_STRING
CODE_POINTS_TO_STRING(unicode_code_points)
Description
Takes an array of Unicode code points
as ARRAY<INT64>
and returns a STRING
.
To convert from a string to an array of code points, see TO_CODE_POINTS.
Return type
STRING
Examples
The following are basic examples using CODE_POINTS_TO_STRING
.
SELECT CODE_POINTS_TO_STRING([65, 255, 513, 1024]) AS string;
/*--------*
| string |
+--------+
| AÿȁЀ |
*--------*/
SELECT CODE_POINTS_TO_STRING([97, 0, 0xF9B5]) AS string;
/*--------*
| string |
+--------+
| a例 |
*--------*/
SELECT CODE_POINTS_TO_STRING([65, 255, NULL, 1024]) AS string;
/*--------*
| string |
+--------+
| NULL |
*--------*/
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 STRING
or BYTE
values into a single result.
The function returns NULL
if any input argument is NULL
.
Return type
STRING
or BYTES
Examples
SELECT CONCAT('T.P.', ' ', 'Bar') as author;
/*---------------------*
| author |
+---------------------+
| T.P. Bar |
*---------------------*/
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(value, suffix)
Description
Takes two STRING
or BYTES
values. Returns TRUE
if suffix
is a suffix of value
.
Return type
BOOL
Examples
SELECT ENDS_WITH('apple', 'e') as example
/*---------*
| example |
+---------+
| True |
*---------*/
FORMAT
FORMAT(format_string_expression, data_type_expression[, ...])
Description
FORMAT
formats a data type expression as a string.
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. In general, 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.data_type_expression
: The value to format as a string. This can be any GoogleSQL data type.
Return type
STRING
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+ |
Integer with commas | FORMAT("%'d", 123456789) | 123,456,789 |
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:
SELECT FORMAT('date: %s!', FORMAT_DATE('%B %d, %Y', date '2015-01-02'));
Returns
date: January 02, 2015!
Supported format specifiers
%[flags][width][.precision]specifier
A format specifier adds formatting when casting a value to a string. It can optionally contain these sub-specifiers:
Additional information about format specifiers:
- %g and %G behavior
- %p and %P behavior
- %t and %T behavior
- Error conditions
- NULL argument handling
- Additional semantic rules
Format specifiers
Specifier | Description | Examples | Types |
d or i |
Decimal integer | 392 |
INT64 |
o |
Octal
Note: If an INT64 value is negative, an error is produced.
|
610 |
INT64 |
x |
Hexadecimal integer
Note: If an INT64 value is negative, an error is produced.
|
7fa |
INT64 |
X |
Hexadecimal integer (uppercase)
Note: If an INT64 value is negative, an error is produced.
|
7FA |
INT64 |
f |
Decimal notation, in [-](integer part).(fractional part) for finite values, and in lowercase for non-finite values | 392.650000 inf nan |
NUMERIC FLOAT32 FLOAT64 |
F |
Decimal notation, in [-](integer part).(fractional part) for finite values, and in uppercase for non-finite values | 392.650000 INF NAN |
NUMERIC FLOAT32 FLOAT64 |
e |
Scientific notation (mantissa/exponent), lowercase | 3.926500e+02 inf nan |
NUMERIC FLOAT32 FLOAT64 |
E |
Scientific notation (mantissa/exponent), uppercase | 3.926500E+02 INF NAN |
NUMERIC FLOAT32 FLOAT64 |
g |
Either decimal notation or scientific notation, depending on the input value's exponent and the specified precision. Lowercase. See %g and %G behavior for details. | 392.65 3.9265e+07 inf nan |
NUMERIC FLOAT32 FLOAT64 |
G |
Either decimal notation or scientific notation, depending on the input value's exponent and the specified precision. Uppercase. See %g and %G behavior for details. |
392.65 3.9265E+07 INF NAN |
NUMERIC FLOAT32 FLOAT64 |
p |
Produces a one-line printable string representing a protocol buffer or JSON. See %p and %P behavior. |
year: 2019 month: 10 {"month":10,"year":2019} |
JSON PROTO |
P |
Produces a multi-line printable string representing a protocol buffer or JSON. See %p and %P behavior. |
year: 2019 month: 10 { "month": 10, "year": 2019 } |
JSON PROTO |
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 and %T behavior.
|
sample 2014‑01‑01 |
Any type |
T |
Produces a string that is a valid GoogleSQL constant with a similar type to the value's type (maybe wider, or maybe string). See %t and %T behavior. |
'sample' b'bytes sample' 1234 2.3 date '2014‑01‑01' |
Any type |
% |
'%%' produces a single '%' | % | n/a |
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 |
# |
|
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> |
|
.* |
The precision is not specified in the format string, but as an additional integer value argument preceding the argument that has to be formatted |
%g and %G behavior
The %g
and %G
format specifiers choose either the decimal notation (like
the %f
and %F
specifiers) or the scientific notation (like the %e
and %E
specifiers), depending on the input value's exponent and the specified
precision.
Let p stand for the specified precision (defaults to 6; 1 if the specified precision is less than 1). The input value is first converted to scientific notation with precision = (p - 1). If the resulting exponent part x is less than -4 or no less than p, the scientific notation with precision = (p - 1) is used; otherwise the decimal notation with precision = (p - 1 - x) is used.
Unless #
flag is present, the trailing zeros after the decimal point
are removed, and the decimal point is also removed if there is no digit after
it.
%p and %P behavior
The %p
format specifier produces a one-line printable string. The %P
format specifier produces a multi-line printable string. You can use these
format specifiers with the following data types:
Type | %p | %P |
PROTO |
PROTO input: message ReleaseDate { required int32 year = 1 [default=2019]; required int32 month = 2 [default=10]; } Produces a one-line printable string representing a protocol buffer: year: 2019 month: 10 |
PROTO input: message ReleaseDate { required int32 year = 1 [default=2019]; required int32 month = 2 [default=10]; } Produces a multi-line printable string representing a protocol buffer: year: 2019 month: 10 |
JSON |
JSON input: JSON ' { "month": 10, "year": 2019 } ' Produces a one-line printable string representing JSON: {"month":10,"year":2019} |
JSON input: JSON ' { "month": 10, "year": 2019 } ' Produces a multi-line printable string representing JSON: { "month": 10, "year": 2019 } |
%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.
The %t
specifier is always meant to be a readable form of the value.
The %T
specifier 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" |
FLOAT32, FLOAT64 |
123.0 (always with .0) 123e+10 inf -inf NaN
|
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" |
BOOL | boolean value | boolean value |
ENUM | EnumName | "EnumName" |
DATE | 2011-02-03 | DATE "2011-02-03" |
TIMESTAMP | 2011-02-03 04:05:06+00 | TIMESTAMP "2011-02-03 04:05:06+00" |
PROTO | one-line printable string representing a protocol buffer. | quoted string literal with one-line printable string representing a protocol buffer. |
ARRAY | [value, value, ...] where values are formatted with %t |
[value, value, ...] where values are formatted with %T |
JSON |
one-line printable string representing JSON.{"name":"apple","stock":3} |
one-line printable string representing a JSON literal.JSON '{"name":"apple","stock":3}' |
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 STRING
s 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-00
Additional semantic rules
FLOAT64
and
FLOAT32
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
GoogleSQL casts these values to STRING
. For %T
,
GoogleSQL 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;
-- Note that the result of FROM_BASE32 is of type BYTES, displayed as a base64-encoded string.
/*-----------*
| byte_data |
+-----------+
| YWJjZGX/ |
*-----------*/
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][string-link-to-base64].
There are several base64 encodings in common use that vary in exactly which
alphabet of 65 ASCII characters are used to encode the 64 digits and padding.
See RFC 4648 for details. This
function expects the alphabet [A-Za-z0-9+/=]
.
Return type
BYTES
Example
SELECT FROM_BASE64('/+A=') AS byte_data;
-- Note that the result of FROM_BASE64 is of type BYTES, displayed as a base64-encoded string.
/*-----------*
| byte_data |
+-----------+
| /+A= |
*-----------*/
To work with an encoding using a different base64 alphabet, you might need to
compose FROM_BASE64
with the REPLACE
function. For instance, the
base64url
url-safe and filename-safe encoding commonly used in web programming
uses -_=
as the last characters rather than +/=
. To decode a
base64url
-encoded string, replace -
and _
with +
and /
respectively.
SELECT FROM_BASE64(REPLACE(REPLACE('_-A=', '-', '+'), '_', '/')) AS binary;
-- Note that the result of FROM_BASE64 is of type BYTES, displayed as a base64-encoded string.
/*--------*
| binary |
+--------+
| /+A= |
*--------*/
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. If the
input STRING
has an odd number of characters, the function acts as if the
input has an additional leading 0
. 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;
-- Note that the result of FROM_HEX is of type BYTES, displayed as a base64-encoded string.
/*------------------+--------------*
| hex_str | bytes_str |
+------------------+--------------+
| 0AF | AAECA6ru7/8= |
| 00010203aaeeefff | AK8= |
| 666f6f626172 | Zm9vYmFy |
*------------------+--------------*/
LENGTH
LENGTH(value)
Description
Returns the length of the STRING
or BYTES
value. The returned
value is in characters for STRING
arguments and in bytes for the BYTES
argument.
Return type
INT64
Examples
SELECT
LENGTH('абвгд') AS string_example,
LENGTH(CAST('абвгд' AS BYTES)) AS bytes_example;
/*----------------+---------------*
| string_example | bytes_example |
+----------------+---------------+
| 5 | 10 |
*----------------+---------------*/
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
SELECT
LOWER('FOO BAR BAZ') AS example
FROM items;
/*-------------*
| example |
+-------------+
| foo bar baz |
*-------------*/
LPAD
LPAD(original_value, return_length[, pattern])
Description
Returns a STRING
or BYTES
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 of type
BYTES
, return_length
is the number of bytes. If original_value
is
of type 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_length
is negativepattern
is empty
Return type
STRING
or BYTES
Examples
SELECT FORMAT('%T', LPAD('c', 5)) AS results
/*---------*
| results |
+---------+
| " c" |
*---------*/
SELECT LPAD('b', 5, 'a') AS results
/*---------*
| results |
+---------+
| aaaab |
*---------*/
SELECT LPAD('abc', 10, 'ghd') AS results
/*------------*
| results |
+------------+
| ghdghdgabc |
*------------*/
SELECT LPAD('abc', 2, 'd') AS results
/*---------*
| results |
+---------+
| ab |
*---------*/
SELECT FORMAT('%T', LPAD(b'abc', 10, b'ghd')) AS results
/*---------------*
| results |
+---------------+
| b"ghdghdgabc" |
*---------------*/
LTRIM
LTRIM(value1[, value2])
Description
Identical to TRIM, but only removes leading characters.
Return type
STRING
or BYTES
Examples
SELECT CONCAT('#', LTRIM(' apple '), '#') AS example
/*-------------*
| example |
+-------------+
| #apple # |
*-------------*/
SELECT LTRIM('***apple***', '*') AS example
/*-----------*
| example |
+-----------+
| apple*** |
*-----------*/
SELECT LTRIM('xxxapplexxx', 'xyz') AS example
/*-----------*
| example |
+-----------+
| applexxx |
*-----------*/
NORMALIZE
NORMALIZE(value[, normalization_mode])
Description
Takes a string value and returns it as a normalized string. If you do not
provide a normalization mode, NFC
is used.
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. |
Return type
STRING
Examples
The following example normalizes different language characters:
SELECT
NORMALIZE('\u00ea') as a,
NORMALIZE('\u0065\u0302') as b,
NORMALIZE('\u00ea') = NORMALIZE('\u0065\u0302') as normalized;
/*---+---+------------*
| a | b | normalized |
+---+---+------------+
| ê | ê | TRUE |
*---+---+------------*/
The following examples normalize different space characters:
SELECT NORMALIZE('Raha\u2004Mahan', NFKC) AS normalized_name
/*-----------------*
| normalized_name |
+-----------------+
| Raha Mahan |
*-----------------*/
SELECT NORMALIZE('Raha\u2005Mahan', NFKC) AS normalized_name
/*-----------------*
| normalized_name |
+-----------------+
| Raha Mahan |
*-----------------*/
SELECT NORMALIZE('Raha\u2006Mahan', NFKC) AS normalized_name
/*-----------------*
| normalized_name |
+-----------------+
| Raha Mahan |
*-----------------*/
SELECT NORMALIZE('Raha Mahan', NFKC) AS normalized_name
/*-----------------*
| normalized_name |
+-----------------+
| Raha Mahan |
*-----------------*/
NORMALIZE_AND_CASEFOLD
NORMALIZE_AND_CASEFOLD(value[, normalization_mode])
Description
Takes a string value and returns it as a normalized string. If you do not
provide a normalization mode, NFC
is used.
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.
Case folding is used for the caseless
comparison of strings. If you need to compare strings and case should not be
considered, use NORMALIZE_AND_CASEFOLD
, otherwise use
NORMALIZE
.
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. |
Return type
STRING
Examples
SELECT
NORMALIZE('The red barn') = NORMALIZE('The Red Barn') AS normalized,
NORMALIZE_AND_CASEFOLD('The red barn')
= NORMALIZE_AND_CASEFOLD('The Red Barn') AS normalized_with_case_folding;
/*------------+------------------------------*
| normalized | normalized_with_case_folding |
+------------+------------------------------+
| FALSE | TRUE |
*------------+------------------------------*/
SELECT
'\u2168' AS a,
'IX' AS b,
NORMALIZE_AND_CASEFOLD('\u2168', NFD)=NORMALIZE_AND_CASEFOLD('IX', NFD) AS nfd,
NORMALIZE_AND_CASEFOLD('\u2168', NFC)=NORMALIZE_AND_CASEFOLD('IX', NFC) AS nfc,
NORMALIZE_AND_CASEFOLD('\u2168', NFKD)=NORMALIZE_AND_CASEFOLD('IX', NFKD) AS nkfd,
NORMALIZE_AND_CASEFOLD('\u2168', NFKC)=NORMALIZE_AND_CASEFOLD('IX', NFKC) AS nkfc;
/*---+----+-------+-------+------+------*
| a | b | nfd | nfc | nkfd | nkfc |
+---+----+-------+-------+------+------+
| Ⅸ | IX | false | false | true | true |
*---+----+-------+-------+------+------*/
SELECT
'\u0041\u030A' AS a,
'\u00C5' AS b,
NORMALIZE_AND_CASEFOLD('\u0041\u030A', NFD)=NORMALIZE_AND_CASEFOLD('\u00C5', NFD) AS nfd,
NORMALIZE_AND_CASEFOLD('\u0041\u030A', NFC)=NORMALIZE_AND_CASEFOLD('\u00C5', NFC) AS nfc,
NORMALIZE_AND_CASEFOLD('\u0041\u030A', NFKD)=NORMALIZE_AND_CASEFOLD('\u00C5', NFKD) AS nkfd,
NORMALIZE_AND_CASEFOLD('\u0041\u030A', NFKC)=NORMALIZE_AND_CASEFOLD('\u00C5', NFKC) AS nkfc;
/*---+----+-------+-------+------+------*
| a | b | nfd | nfc | nkfd | nkfc |
+---+----+-------+-------+------+------+
| Å | Å | true | true | true | true |
*---+----+-------+-------+------+------*/
REGEXP_CONTAINS
REGEXP_CONTAINS(value, regexp)
Description
Returns TRUE
if value
is a partial match for the regular expression,
regexp
.
If the regexp
argument is invalid, the function returns an error.
You can search for a full match by using ^
(beginning of text) and $
(end of
text). Due to regular expression operator precedence, it is good practice to use
parentheses around everything between ^
and $
.
Return type
BOOL
Examples
The following queries check to see if an email is valid:
SELECT
'foo@example.com' AS email,
REGEXP_CONTAINS('foo@example.com', r'@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+') AS is_valid
/*-----------------+----------*
| email | is_valid |
+-----------------+----------+
| foo@example.com | TRUE |
*-----------------+----------*/
```
```sql
SELECT
'www.example.net' AS email,
REGEXP_CONTAINS('www.example.net', r'@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+') AS is_valid
/*-----------------+----------*
| email | is_valid |
+-----------------+----------+
| www.example.net | FALSE |
*-----------------+----------*/
```
The following queries check to see if an email is valid. They
perform a full match, using `^` and `$`. Due to regular expression operator
precedence, it is good practice to use parentheses around everything between `^`
and `$`.
```sql
SELECT
'a@foo.com' AS email,
REGEXP_CONTAINS('a@foo.com', r'^([\w.+-]+@foo\.com|[\w.+-]+@bar\.org)$') AS valid_email_address,
REGEXP_CONTAINS('a@foo.com', r'^[\w.+-]+@foo\.com|[\w.+-]+@bar\.org$') AS without_parentheses;
/*----------------+---------------------+---------------------*
| email | valid_email_address | without_parentheses |
+----------------+---------------------+---------------------+
| a@foo.com | true | true |
*----------------+---------------------+---------------------*/
SELECT
'a@foo.computer' AS email,
REGEXP_CONTAINS('a@foo.computer', r'^([\w.+-]+@foo\.com|[\w.+-]+@bar\.org)$') AS valid_email_address,
REGEXP_CONTAINS('a@foo.computer', r'^[\w.+-]+@foo\.com|[\w.+-]+@bar\.org$') AS without_parentheses;
/*----------------+---------------------+---------------------*
| email | valid_email_address | without_parentheses |
+----------------+---------------------+---------------------+
| a@foo.computer | false | true |
*----------------+---------------------+---------------------*/
SELECT
'b@bar.org' AS email,
REGEXP_CONTAINS('b@bar.org', r'^([\w.+-]+@foo\.com|[\w.+-]+@bar\.org)$') AS valid_email_address,
REGEXP_CONTAINS('b@bar.org', r'^[\w.+-]+@foo\.com|[\w.+-]+@bar\.org$') AS without_parentheses;
/*----------------+---------------------+---------------------*
| email | valid_email_address | without_parentheses |
+----------------+---------------------+---------------------+
| b@bar.org | true | true |
*----------------+---------------------+---------------------*/
SELECT
'!b@bar.org' AS email,
REGEXP_CONTAINS('!b@bar.org', r'^([\w.+-]+@foo\.com|[\w.+-]+@bar\.org)$') AS valid_email_address,
REGEXP_CONTAINS('!b@bar.org', r'^[\w.+-]+@foo\.com|[\w.+-]+@bar\.org$') AS without_parentheses;
/*----------------+---------------------+---------------------*
| email | valid_email_address | without_parentheses |
+----------------+---------------------+---------------------+
| !b@bar.org | false | true |
*----------------+---------------------+---------------------*/
SELECT
'c@buz.net' AS email,
REGEXP_CONTAINS('c@buz.net', r'^([\w.+-]+@foo\.com|[\w.+-]+@bar\.org)$') AS valid_email_address,
REGEXP_CONTAINS('c@buz.net', r'^[\w.+-]+@foo\.com|[\w.+-]+@bar\.org$') AS without_parentheses;
/*----------------+---------------------+---------------------*
| email | valid_email_address | without_parentheses |
+----------------+---------------------+---------------------+
| c@buz.net | false | false |
*----------------+---------------------+---------------------*/
REGEXP_EXTRACT
REGEXP_EXTRACT(value, regexp)
Description
Returns the first substring in value
that matches the
re2 regular expression,
regexp
. Returns NULL
if there is no match.
If the regular expression contains a capturing group ((...)
), and there is a
match for that capturing group, that match is returned. If there
are multiple matches for a capturing group, the first match is returned.
Returns an error if:
- The regular expression is invalid
- The regular expression has more than one capturing group
Return type
STRING
or BYTES
Examples
SELECT REGEXP_EXTRACT('foo@example.com', r'^[a-zA-Z0-9_.+-]+') AS user_name
/*-----------*
| user_name |
+-----------+
| foo |
*-----------*/
SELECT REGEXP_EXTRACT('foo@example.com', r'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.([a-zA-Z0-9-.]+$)')
/*------------------*
| top_level_domain |
+------------------+
| com |
*------------------*/
SELECT
REGEXP_EXTRACT('ab', '.b') AS result_a,
REGEXP_EXTRACT('ab', '(.)b') AS result_b,
REGEXP_EXTRACT('xyztb', '(.)+b') AS result_c,
REGEXP_EXTRACT('ab', '(z)?b') AS result_d
/*-------------------------------------------*
| result_a | result_b | result_c | result_d |
+-------------------------------------------+
| ab | a | t | NULL |
*-------------------------------------------*/
REGEXP_EXTRACT_ALL
REGEXP_EXTRACT_ALL(value, regexp)
Description
Returns an array of all substrings of value
that match the
re2 regular expression, regexp
. Returns an empty array
if there is no match.
If the regular expression contains a capturing group ((...)
), and there is a
match for that capturing group, that match is added to the results.
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.
Returns an error if:
- The regular expression is invalid
- The regular expression has more than one capturing group
Return type
ARRAY<STRING>
or ARRAY<BYTES>
Examples
SELECT REGEXP_EXTRACT_ALL('Try `func(x)` or `func(y)`', '`(.+?)`') AS example
/*--------------------*
| example |
+--------------------+
| [func(x), func(y)] |
*--------------------*/
REGEXP_REPLACE
REGEXP_REPLACE(value, regexp, replacement)
Description
Returns a STRING
where all substrings of value
that
match regular expression regexp
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
regexp
pattern. Use \0 to refer to the entire matching text.
To add a backslash in your regular expression, you must first escape it. For
example, SELECT REGEXP_REPLACE('abc', 'b(.)', 'X\\1');
returns aXc
. You can
also use raw strings to remove one layer of
escaping, for example SELECT REGEXP_REPLACE('abc', 'b(.)', r'X\1');
.
The REGEXP_REPLACE
function only replaces non-overlapping matches. For
example, replacing ana
within banana
results in only one replacement, not
two.
If the regexp
argument is not a valid regular expression, this function
returns an error.
Return type
STRING
or BYTES
Examples
SELECT REGEXP_REPLACE('# Heading', r'^# ([a-zA-Z0-9\s]+$)', '<h1>\\1</h1>') AS html
/*--------------------------*
| html |
+--------------------------+
| <h1>Heading</h1> |
*--------------------------*/
REPEAT
REPEAT(original_value, repetitions)
Description
Returns a STRING
or BYTES
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 returns an error if the repetitions
value is negative.
Return type
STRING
or BYTES
Examples
SELECT REPEAT('abc', 3) AS results
/*-----------*
| results |
|-----------|
| abcabcabc |
*-----------*/
SELECT REPEAT('abc', NULL) AS results
/*---------*
| results |
|---------|
| NULL |
*---------*/
SELECT REPEAT(NULL, 3) AS results
/*---------*
| results |
|---------|
| NULL |
*---------*/
REPLACE
REPLACE(original_value, from_pattern, to_pattern)
Description
Replaces all occurrences of from_pattern
with to_pattern
in
original_value
. If from_pattern
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 |
*--------------------*/
REVERSE
REVERSE(value)
Description
Returns the reverse of the input STRING
or BYTES
.
Return type
STRING
or BYTES
Examples
SELECT REVERSE('abc') AS results
/*---------*
| results |
+---------+
| cba |
*---------*/
SELECT FORMAT('%T', REVERSE(b'1a3')) AS results
/*---------*
| results |
+---------+
| b"3a1" |
*---------*/
RPAD
RPAD(original_value, return_length[, pattern])
Description
Returns a STRING
or BYTES
value that consists of original_value
appended
with pattern
. The return_length
parameter 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_length
is negativepattern
is empty
Return type
STRING
or BYTES
Examples
SELECT FORMAT('%T', RPAD('c', 5)) AS results
/*---------*
| results |
+---------+
| "c " |
*---------*/
SELECT RPAD('b', 5, 'a') AS results
/*---------*
| results |
+---------+
| baaaa |
*---------*/
SELECT RPAD('abc', 10, 'ghd') AS results
/*------------*
| results |
+------------+
| abcghdghdg |
*------------*/
SELECT RPAD('abc', 2, 'd') AS results
/*---------*
| results |
+---------+
| ab |
*---------*/
SELECT FORMAT('%T', RPAD(b'abc', 10, b'ghd')) AS results
/*---------------*
| results |
+---------------+
| b"abcghdghdg" |
*---------------*/
RTRIM
RTRIM(value1[, value2])
Description
Identical to TRIM, but only removes trailing characters.
Return type
STRING
or BYTES
Examples
SELECT RTRIM('***apple***', '*') AS example
/*-----------*
| example |
+-----------+
| ***apple |
*-----------*/
SELECT RTRIM('applexxz', 'xyz') AS example
/*---------*
| example |
+---------+
| apple |
*---------*/
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;
SOUNDEX
SOUNDEX(value)
Description
Returns a STRING
that represents the
Soundex code for value
.
SOUNDEX produces a phonetic representation of a string. It indexes words by sound, as pronounced in English. It is typically used to help determine whether two strings, such as the family names Levine and Lavine, or the words to and too, have similar English-language pronunciation.
The result of the SOUNDEX consists of a letter followed by 3 digits. Non-latin
characters are ignored. If the remaining string is empty after removing
non-Latin characters, an empty STRING
is returned.
Return type
STRING
Examples
SELECT 'Ashcraft' AS value, SOUNDEX('Ashcraft') AS soundex
/*----------------------+---------*
| value | soundex |
+----------------------+---------+
| Ashcraft | A261 |
*----------------------+---------*/
SPLIT
SPLIT(value[, delimiter])
Description
Splits a STRING
or BYTES
value, using a delimiter. The delimiter
argument
must be a literal character or sequence of characters. You can't split with a
regular expression.
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<STRING>
or ARRAY<BYTES>
Examples
WITH letters AS
(SELECT '' as letter_group
UNION ALL
SELECT 'a' as letter_group
UNION ALL
SELECT 'b c d' as letter_group)
SELECT SPLIT(letter_group, ' ') as example
FROM letters;
/*----------------------*
| example |
+----------------------+
| [] |
| [a] |
| [b, c, d] |
*----------------------*/
STARTS_WITH
STARTS_WITH(value, prefix)
Description
Takes two STRING
or BYTES
values. Returns TRUE
if prefix
is a
prefix of value
.
Return type
BOOL
Examples
SELECT STARTS_WITH('bar', 'b') AS example
/*---------*
| example |
+---------+
| True |
*---------*/
STRPOS
STRPOS(value, subvalue)
Description
Takes two STRING
or BYTES
values. Returns the 1-based position of the first
occurrence of subvalue
inside value
. Returns 0
if subvalue
is not found.
Return type
INT64
Examples
SELECT STRPOS('foo@example.com', '@') AS example
/*---------*
| example |
+---------+
| 4 |
*---------*/
SUBSTR
SUBSTR(value, position[, length])
Description
Gets a portion (substring) of the supplied STRING
or BYTES
value.
The position
argument is an integer specifying the starting position of the
substring.
- If
position
is1
, the substring starts from the first character or byte. - If
position
is0
or less than-LENGTH(value)
,position
is set to1
, and the substring starts from the first character or byte. - If
position
is greater than the length ofvalue
, the function produces an empty substring. - If
position
is negative, the function counts from the end ofvalue
, with-1
indicating the last character or byte.
The length
argument specifies the maximum number of characters or bytes to
return.
- If
length
is not specified, the function produces a substring that starts at the specified position and ends at the last character or byte ofvalue
. - If
length
is0
, the function produces an empty substring. - If
length
is negative, the function produces an error. - The returned substring may be shorter than
length
, for example, whenlength
exceeds the length ofvalue
, or when the starting position of the substring pluslength
is greater than the length ofvalue
.
Return type
STRING
or BYTES
Examples
SELECT SUBSTR('apple', 2) AS example
/*---------*
| example |
+---------+
| pple |
*---------*/
SELECT SUBSTR('apple', 2, 2) AS example
/*---------*
| example |
+---------+
| pp |
*---------*/
SELECT SUBSTR('apple', -2) AS example
/*---------*
| example |
+---------+
| le |
*---------*/
SELECT SUBSTR('apple', 1, 123) AS example
/*---------*
| example |
+---------+
| apple |
*---------*/
SELECT SUBSTR('apple', 123) AS example
/*---------*
| example |
+---------+
| |
*---------*/
SELECT SUBSTR('apple', 123, 5) AS example
/*---------*
| example |
+---------+
| |
*---------*/
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.
There are several base64 encodings in common use that vary in exactly which
alphabet of 65 ASCII characters are used to encode the 64 digits and padding.
See RFC 4648 for details. This
function adds padding and uses the alphabet [A-Za-z0-9+/=]
.
Return type
STRING
Example
SELECT TO_BASE64(b'\377\340') AS base64_string;
/*---------------*
| base64_string |
+---------------+
| /+A= |
*---------------*/
To work with an encoding using a different base64 alphabet, you might need to
compose TO_BASE64
with the REPLACE
function. For instance, the
base64url
url-safe and filename-safe encoding commonly used in web programming
uses -_=
as the last characters rather than +/=
. To encode a
base64url
-encoded string, replace +
and /
with -
and _
respectively.
SELECT REPLACE(REPLACE(TO_BASE64(b'\377\340'), '+', '-'), '/', '_') as websafe_base64;
/*----------------*
| websafe_base64 |
+----------------+
| _-A= |
*----------------*/
TO_CODE_POINTS
TO_CODE_POINTS(value)
Description
Takes a STRING
or BYTES
value and returns an array of INT64
values that
represent code points or extended ASCII character values.
- If
value
is aSTRING
, each element in the returned array represents a code point. Each code point falls within the range of [0, 0xD7FF] and [0xE000, 0x10FFFF]. - If
value
isBYTES
, 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<INT64>
Examples
The following examples get the code points for each element in an array of words.
SELECT
'foo' AS word,
TO_CODE_POINTS('foo') AS code_points
/*---------+------------------------------------*
| word | code_points |
+---------+------------------------------------+
| foo | [102, 111, 111] |
*---------+------------------------------------*/
SELECT
'bar' AS word,
TO_CODE_POINTS('bar') AS code_points
/*---------+------------------------------------*
| word | code_points |
+---------+------------------------------------+
| bar | [98, 97, 114] |
*---------+------------------------------------*/
SELECT
'baz' AS word,
TO_CODE_POINTS('baz') AS code_points
/*---------+------------------------------------*
| word | code_points |
+---------+------------------------------------+
| baz | [98, 97, 122] |
*---------+------------------------------------*/
SELECT
'giraffe' AS word,
TO_CODE_POINTS('giraffe') AS code_points
/*---------+------------------------------------*
| word | code_points |
+---------+------------------------------------+
| giraffe | [103, 105, 114, 97, 102, 102, 101] |
*---------+------------------------------------*/
SELECT
'llama' AS word,
TO_CODE_POINTS('llama') AS code_points
/*---------+------------------------------------*
| word | code_points |
+---------+------------------------------------+
| llama | [108, 108, 97, 109, 97] |
*---------+------------------------------------*/
The following examples convert integer representations of BYTES
to their
corresponding ASCII character values.
SELECT
b'\x66\x6f\x6f' AS bytes_value,
TO_CODE_POINTS(b'\x66\x6f\x6f') AS bytes_value_as_integer
/*------------------+------------------------*
| bytes_value | bytes_value_as_integer |
+------------------+------------------------+
| foo | [102, 111, 111] |
*------------------+------------------------*/
SELECT
b'\x00\x01\x10\xff' AS bytes_value,
TO_CODE_POINTS(b'\x00\x01\x10\xff') AS bytes_value_as_integer
/*------------------+------------------------*
| bytes_value | bytes_value_as_integer |
+------------------+------------------------+
| \x00\x01\x10\xff | [0, 1, 16, 255] |
*------------------+------------------------*/
The following example demonstrates the difference between a BYTES
result and a
STRING
result. 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.
SELECT TO_CODE_POINTS(b'Ā') AS b_result, TO_CODE_POINTS('Ā') AS s_result;
/*------------+----------*
| b_result | s_result |
+------------+----------+
| [196, 128] | [256] |
*------------+----------*/
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
SELECT
b'\x00\x01\x02\x03\xAA\xEE\xEF\xFF' AS byte_string,
TO_HEX(b'\x00\x01\x02\x03\xAA\xEE\xEF\xFF') AS hex_string
/*----------------------------------+------------------*
| byte_string | hex_string |
+----------------------------------+------------------+
| \x00\x01\x02\x03\xaa\xee\xef\xff | 00010203aaeeefff |
*----------------------------------+------------------*/
TRIM
TRIM(value_to_trim[, set_of_characters_to_remove])
Description
Takes a STRING
or BYTES
value to trim.
If the value to trim is a STRING
, removes from this value all leading and
trailing Unicode code points in set_of_characters_to_remove
.
The set of code points is optional. If it is not specified, all
whitespace characters are removed from the beginning and end of the
value to trim.
If the value to trim is BYTES
, removes from this value all leading and
trailing bytes in set_of_characters_to_remove
. The set of bytes is required.
Return type
STRING
ifvalue_to_trim
is aSTRING
value.BYTES
ifvalue_to_trim
is aBYTES
value.
Examples
In the following example, all leading and trailing whitespace characters are
removed from item
because set_of_characters_to_remove
is not specified.
SELECT CONCAT('#', TRIM( ' apple '), '#') AS example
/*----------*
| example |
+----------+
| #apple# |
*----------*/
In the following example, all leading and trailing *
characters are removed
from 'apple'.
SELECT TRIM('***apple***', '*') AS example
/*---------*
| example |
+---------+
| apple |
*---------*/
In the following example, all leading and trailing x
, y
, and z
characters
are removed from 'xzxapplexxy'.
SELECT TRIM('xzxapplexxy', 'xyz') as example
/*---------*
| example |
+---------+
| apple |
*---------*/
In the following example, examine how TRIM
interprets characters as
Unicode code-points. If your trailing character set contains a combining
diacritic mark over a particular letter, TRIM
might strip the
same diacritic mark from a different letter.
SELECT
TRIM('abaW̊', 'Y̊') AS a,
TRIM('W̊aba', 'Y̊') AS b,
TRIM('abaŪ̊', 'Y̊') AS c,
TRIM('Ū̊aba', 'Y̊') AS d
/*------+------+------+------*
| a | b | c | d |
+------+------+------+------+
| abaW | W̊aba | abaŪ | Ūaba |
*------+------+------+------*/
In the following example, all leading and trailing b'n'
, b'a'
, b'\xab'
bytes are removed from item
.
SELECT b'apple', TRIM(b'apple', b'na\xab') AS example
-- Note that the result of TRIM is of type BYTES, displayed as a base64-encoded string.
/*----------------------+------------------*
| item | example |
+----------------------+------------------+
| YXBwbGU= | cHBsZQ== |
*----------------------+------------------*/
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
SELECT UPPER('foo') AS example
/*---------*
| example |
+---------+
| FOO |
*---------*/