GoogleSQL for Spanner supports the following functions, which can retrieve and transform JSON data.
Categories
The JSON functions are grouped into the following categories based on their behavior:
Category | Functions | Description |
Extractors |
JSON_QUERY JSON_VALUE JSON_QUERY_ARRAY JSON_VALUE_ARRAY |
Functions that extract JSON data. |
Lax converters |
LAX_BOOL LAX_FLOAT64 LAX_INT64 LAX_STRING |
Functions that flexibly convert a JSON value to an SQL value without returning errors. |
Converters |
BOOL BOOL_ARRAY FLOAT64 FLOAT64_ARRAY FLOAT32 FLOAT32_ARRAY INT64 INT64_ARRAY STRING STRING_ARRAY |
Functions that convert a JSON value to a SQL value. |
Other converters |
PARSE_JSON TO_JSON TO_JSON_STRING |
Other conversion functions from or to JSON. |
Constructors |
JSON_ARRAY JSON_OBJECT |
Functions that create JSON. |
Accessors |
JSON_TYPE |
Functions that provide access to JSON properties. |
Function list
Name | Summary |
---|---|
BOOL
|
Converts a JSON boolean to a SQL BOOL value.
|
BOOL
|
Converts a JSON array of booleans to a SQL ARRAY<BOOL> value. |
FLOAT64
|
Converts a JSON number to a SQL
FLOAT64 value.
|
FLOAT64_ARRAY
|
Converts a JSON array of numbers to a SQL ARRAY<FLOAT64> value. |
FLOAT32
|
Converts a JSON number to a SQL FLOAT32 value. |
FLOAT32_ARRAY
|
Converts a JSON array of numbers to a SQL ARRAY<FLOAT32> value. |
INT64
|
Converts a JSON number to a SQL INT64 value.
|
INT64_ARRAY
|
Converts a JSON array of numbers to a SQL ARRAY<INT64> value. |
JSON_ARRAY
|
Creates a JSON array. |
JSON_OBJECT
|
Creates a JSON object. |
JSON_QUERY
|
Extracts a JSON value and converts it to a SQL
JSON-formatted STRING
or
JSON
value.
|
JSON_QUERY_ARRAY
|
Extracts a JSON array and converts it to
a SQL ARRAY<JSON-formatted STRING>
or
ARRAY<JSON>
value.
|
JSON_TYPE
|
Gets the JSON type of the outermost JSON value and converts the name of
this type to a SQL STRING value.
|
JSON_VALUE
|
Extracts a JSON scalar value and converts it to a SQL
STRING value.
|
JSON_VALUE_ARRAY
|
Extracts a JSON array of scalar values and converts it to a SQL
ARRAY<STRING> value.
|
LAX_BOOL
|
Attempts to convert a JSON value to a SQL BOOL value.
|
LAX_FLOAT64
|
Attempts to convert a JSON value to a
SQL FLOAT64 value.
|
LAX_INT64
|
Attempts to convert a JSON value to a SQL INT64 value.
|
LAX_STRING
|
Attempts to convert a JSON value to a SQL STRING value.
|
PARSE_JSON
|
Converts a JSON-formatted STRING value to a
JSON value.
|
STRING
|
Converts a JSON string to a SQL STRING value.
|
STRING_ARRAY
|
Converts a JSON array of strings to a SQL ARRAY<STRING>
value.
|
TO_JSON
|
Converts a SQL value to a JSON value. |
TO_JSON_STRING
|
Converts a JSON value to a SQL JSON-formatted STRING value.
|
BOOL
BOOL(json_expr)
Description
Converts a JSON boolean to a SQL BOOL
value.
Arguments:
json_expr
: JSON. For example:JSON 'true'
If the JSON value is not a boolean, an error is produced. If the expression is SQL
NULL
, the function returns SQLNULL
.
Return type
BOOL
Examples
SELECT BOOL(JSON 'true') AS vacancy;
/*---------*
| vacancy |
+---------+
| true |
*---------*/
SELECT BOOL(JSON_QUERY(JSON '{"hotel class": "5-star", "vacancy": true}', "$.vacancy")) AS vacancy;
/*---------*
| vacancy |
+---------+
| true |
*---------*/
The following examples show how invalid requests are handled:
-- An error is thrown if JSON is not of type bool.
SELECT BOOL(JSON '123') AS result; -- Throws an error
SELECT BOOL(JSON 'null') AS result; -- Throws an error
SELECT SAFE.BOOL(JSON '123') AS result; -- Returns a SQL NULL
BOOL_ARRAY
BOOL_ARRAY(json_expr)
Description
Converts a JSON array of booleans to a SQL ARRAY<BOOL>
value.
Arguments:
json_expr
: JSON. For example:JSON '[true]'
If the JSON value is not an array of booleans, an error is produced. If the expression is SQL
NULL
, the function returns SQLNULL
.
Return type
ARRAY<BOOL>
Examples
SELECT BOOL_ARRAY(JSON '[true, false]') AS vacancies;
/*---------------*
| vacancies |
+---------------+
| [true, false] |
*---------------*/
The following examples show how invalid requests are handled:
-- An error is thrown if the JSON is not an array of booleans.
SELECT BOOL_ARRAY(JSON '[123]') AS result; -- Throws an error
SELECT BOOL_ARRAY(JSON '[null]') AS result; -- Throws an error
SELECT BOOL_ARRAY(JSON 'null') AS result; -- Throws an error
FLOAT64
FLOAT64(
json_expr
[, wide_number_mode => { 'exact' | 'round' } ]
)
Description
Converts a JSON number to a SQL FLOAT64
value.
Arguments:
json_expr
: JSON. For example:JSON '9.8'
If the JSON value is not a number, an error is produced. If the expression is a SQL
NULL
, the function returns SQLNULL
.wide_number_mode
: A named argument with aSTRING
value. Defines what happens with a number that can't be represented as aFLOAT64
without loss of precision. This argument accepts one of the two case-sensitive values:exact
: The function fails if the result cannot be represented as aFLOAT64
without loss of precision.round
(default): The numeric value stored in JSON will be rounded toFLOAT64
. If such rounding is not possible, the function fails.
Return type
FLOAT64
Examples
SELECT FLOAT64(JSON '9.8') AS velocity;
/*----------*
| velocity |
+----------+
| 9.8 |
*----------*/
SELECT FLOAT64(JSON_QUERY(JSON '{"vo2_max": 39.1, "age": 18}', "$.vo2_max")) AS vo2_max;
/*---------*
| vo2_max |
+---------+
| 39.1 |
*---------*/
SELECT FLOAT64(JSON '18446744073709551615', wide_number_mode=>'round') as result;
/*------------------------*
| result |
+------------------------+
| 1.8446744073709552e+19 |
*------------------------*/
SELECT FLOAT64(JSON '18446744073709551615') as result;
/*------------------------*
| result |
+------------------------+
| 1.8446744073709552e+19 |
*------------------------*/
The following examples show how invalid requests are handled:
-- An error is thrown if JSON is not of type FLOAT64.
SELECT FLOAT64(JSON '"strawberry"') AS result;
SELECT FLOAT64(JSON 'null') AS result;
-- An error is thrown because `wide_number_mode` is case-sensitive and not "exact" or "round".
SELECT FLOAT64(JSON '123.4', wide_number_mode=>'EXACT') as result;
SELECT FLOAT64(JSON '123.4', wide_number_mode=>'exac') as result;
-- An error is thrown because the number cannot be converted to DOUBLE without loss of precision
SELECT FLOAT64(JSON '18446744073709551615', wide_number_mode=>'exact') as result;
-- Returns a SQL NULL
SELECT SAFE.FLOAT64(JSON '"strawberry"') AS result;
FLOAT64_ARRAY
FLOAT64_ARRAY(
json_expr
[, wide_number_mode => { 'exact' | 'round' } ]
)
Description
Converts a JSON array of numbers to a SQL ARRAY<FLOAT64>
value.
Arguments:
json_expr
: JSON. For example:JSON '[9.8]'
If the JSON value is not an array of numbers, an error is produced. If the expression is a SQL
NULL
, the function returns SQLNULL
.wide_number_mode
: A named argument that takes aSTRING
value. Defines what happens with a number that can't be represented as aFLOAT64
without loss of precision. This argument accepts one of the two case-sensitive values:exact
: The function fails if the result cannot be represented as aFLOAT64
without loss of precision.round
(default): The numeric value stored in JSON will be rounded toFLOAT64
. If such rounding is not possible, the function fails.
Return type
ARRAY<FLOAT64>
Examples
SELECT FLOAT64_ARRAY(JSON '[9, 9.8]') AS velocities;
/*-------------*
| velocities |
+-------------+
| [9.0, 9.8] |
*-------------*/
SELECT FLOAT64_ARRAY(JSON '[18446744073709551615]', wide_number_mode=>'round') as result;
/*--------------------------*
| result |
+--------------------------+
| [1.8446744073709552e+19] |
*--------------------------*/
SELECT FLOAT64_ARRAY(JSON '[18446744073709551615]') as result;
/*--------------------------*
| result |
+--------------------------+
| [1.8446744073709552e+19] |
*--------------------------*/
The following examples show how invalid requests are handled:
-- An error is thrown if the JSON is not an array of numbers.
SELECT FLOAT64_ARRAY(JSON '["strawberry"]') AS result;
SELECT FLOAT64_ARRAY(JSON '[null]') AS result;
SELECT FLOAT64_ARRAY(JSON 'null') AS result;
-- An error is thrown because `wide_number_mode` is case-sensitive and not "exact" or "round".
SELECT FLOAT64_ARRAY(JSON '[123.4]', wide_number_mode=>'EXACT') as result;
SELECT FLOAT64_ARRAY(JSON '[123.4]', wide_number_mode=>'exac') as result;
-- An error is thrown because the number cannot be converted to DOUBLE without loss of precision
SELECT FLOAT64_ARRAY(JSON '[18446744073709551615]', wide_number_mode=>'exact') as result;
FLOAT32
FLOAT32(
json_expr
[, [ wide_number_mode => ] { 'exact' | 'round' } ]
)
Description
Converts a JSON number to a SQL FLOAT32
value.
Arguments:
json_expr
: JSON. For example:JSON '9.8'
If the JSON value is not a number, an error is produced. If the expression is a SQL
NULL
, the function returns SQLNULL
.wide_number_mode
: A named argument with aSTRING
value. Defines what happens with a number that cannot be represented as aFLOAT32
without loss of precision. This argument accepts one of the two case-sensitive values:exact
: The function fails if the result cannot be represented as aFLOAT32
without loss of precision.round
(default): The numeric value stored in JSON will be rounded toFLOAT32
. If such rounding is not possible, the function fails.
Return type
FLOAT32
Examples
SELECT FLOAT32(JSON '9.8') AS velocity;
/*----------*
| velocity |
+----------+
| 9.8 |
*----------*/
SELECT FLOAT32(JSON_QUERY(JSON '{"vo2_max": 39.1, "age": 18}', "$.vo2_max")) AS vo2_max;
/*---------*
| vo2_max |
+---------+
| 39.1 |
*---------*/
SELECT FLOAT32(JSON '16777217', wide_number_mode=>'round') as result;
/*------------*
| result |
+------------+
| 16777216.0 |
*------------*/
SELECT FLOAT32(JSON '16777216') as result;
/*------------*
| result |
+------------+
| 16777216.0 |
*------------*/
The following examples show how invalid requests are handled:
-- An error is thrown if JSON is not of type FLOAT32.
SELECT FLOAT32(JSON '"strawberry"') AS result;
SELECT FLOAT32(JSON 'null') AS result;
-- An error is thrown because `wide_number_mode` is case-sensitive and not "exact" or "round".
SELECT FLOAT32(JSON '123.4', wide_number_mode=>'EXACT') as result;
SELECT FLOAT32(JSON '123.4', wide_number_mode=>'exac') as result;
-- An error is thrown because the number cannot be converted to FLOAT without loss of precision
SELECT FLOAT32(JSON '16777217', wide_number_mode=>'exact') as result;
-- Returns a SQL NULL
SELECT SAFE.FLOAT32(JSON '"strawberry"') AS result;
FLOAT32_ARRAY
FLOAT32_ARRAY(
json_expr
[, wide_number_mode => { 'exact' | 'round' } ]
)
Description
Converts a JSON array of numbers to a SQL ARRAY<FLOAT32>
value.
Arguments:
json_expr
: JSON. For example:JSON '[9.8]'
If the JSON value is not an array of numbers, an error is produced. If the expression is a SQL
NULL
, the function returns SQLNULL
.wide_number_mode
: A named argument with aSTRING
value. Defines what happens with a number that can't be represented as aFLOAT32
without loss of precision. This argument accepts one of the two case-sensitive values:exact
: The function fails if the result cannot be represented as aFLOAT32
without loss of precision.round
(default): The numeric value stored in JSON will be rounded toFLOAT32
. If such rounding is not possible, the function fails.
Return type
ARRAY<FLOAT32>
Examples
SELECT FLOAT32_ARRAY(JSON '[9, 9.8]') AS velocities;
/*-------------*
| velocities |
+-------------+
| [9.0, 9.8] |
*-------------*/
SELECT FLOAT32_ARRAY(JSON '[16777217]', wide_number_mode=>'round') as result;
/*--------------*
| result |
+--------------+
| [16777216.0] |
*--------------*/
SELECT FLOAT32_ARRAY(JSON '[16777216]') as result;
/*--------------*
| result |
+--------------+
| [16777216.0] |
*--------------*/
The following examples show how invalid requests are handled:
-- An error is thrown if the JSON is not an array of numbers in FLOAT32 domain.
SELECT FLOAT32_ARRAY(JSON '["strawberry"]') AS result;
SELECT FLOAT32_ARRAY(JSON '[null]') AS result;
SELECT FLOAT32_ARRAY(JSON 'null') AS result;
-- An error is thrown because `wide_number_mode` is case-sensitive and not "exact" or "round".
SELECT FLOAT32_ARRAY(JSON '[123.4]', wide_number_mode=>'EXACT') as result;
SELECT FLOAT32_ARRAY(JSON '[123.4]', wide_number_mode=>'exac') as result;
-- An error is thrown because the number cannot be converted to FLOAT without loss of precision
SELECT FLOAT32_ARRAY(JSON '[16777217]', wide_number_mode=>'exact') as result;
INT64
INT64(json_expr)
Description
Converts a JSON number to a SQL INT64
value.
Arguments:
json_expr
: JSON. For example:JSON '999'
If the JSON value is not a number, or the JSON number is not in the SQL
INT64
domain, an error is produced. If the expression is SQLNULL
, the function returns SQLNULL
.
Return type
INT64
Examples
SELECT INT64(JSON '2005') AS flight_number;
/*---------------*
| flight_number |
+---------------+
| 2005 |
*---------------*/
SELECT INT64(JSON_QUERY(JSON '{"gate": "A4", "flight_number": 2005}', "$.flight_number")) AS flight_number;
/*---------------*
| flight_number |
+---------------+
| 2005 |
*---------------*/
SELECT INT64(JSON '10.0') AS score;
/*-------*
| score |
+-------+
| 10 |
*-------*/
The following examples show how invalid requests are handled:
-- An error is thrown if JSON is not a number or cannot be converted to a 64-bit integer.
SELECT INT64(JSON '10.1') AS result; -- Throws an error
SELECT INT64(JSON '"strawberry"') AS result; -- Throws an error
SELECT INT64(JSON 'null') AS result; -- Throws an error
SELECT SAFE.INT64(JSON '"strawberry"') AS result; -- Returns a SQL NULL
INT64_ARRAY
INT64_ARRAY(json_expr)
Description
Converts a JSON array of numbers to a SQL INT64_ARRAY
value.
Arguments:
json_expr
: JSON. For example:JSON '[999]'
If the JSON value is not an array of numbers, or the JSON numbers are not in the SQL
INT64
domain, an error is produced. If the expression is SQLNULL
, the function returns SQLNULL
.
Return type
ARRAY<INT64>
Examples
SELECT INT64_ARRAY(JSON '[2005, 2003]') AS flight_numbers;
/*----------------*
| flight_numbers |
+----------------+
| [2005, 2003] |
*----------------*/
SELECT INT64_ARRAY(JSON '[10.0]') AS scores;
/*--------*
| scores |
+--------+
| [10] |
*--------*/
The following examples show how invalid requests are handled:
-- An error is thrown if the JSON is not an array of numbers in INT64 domain.
SELECT INT64_ARRAY(JSON '[10.1]') AS result; -- Throws an error
SELECT INT64_ARRAY(JSON '["strawberry"]') AS result; -- Throws an error
SELECT INT64_ARRAY(JSON '[null]') AS result; -- Throws an error
SELECT INT64_ARRAY(JSON 'null') AS result; -- Throws an error
JSON_ARRAY
JSON_ARRAY([value][, ...])
Description
Creates a JSON array from zero or more SQL values.
Arguments:
value
: A JSON encoding-supported value to add to a JSON array.
Return type
JSON
Examples
The following query creates a JSON array with one value in it:
SELECT JSON_ARRAY(10) AS json_data
/*-----------*
| json_data |
+-----------+
| [10] |
*-----------*/
You can create a JSON array with an empty JSON array in it. For example:
SELECT JSON_ARRAY([]) AS json_data
/*-----------*
| json_data |
+-----------+
| [[]] |
*-----------*/
SELECT JSON_ARRAY(10, 'foo', NULL) AS json_data
/*-----------------*
| json_data |
+-----------------+
| [10,"foo",null] |
*-----------------*/
SELECT JSON_ARRAY(STRUCT(10 AS a, 'foo' AS b)) AS json_data
/*----------------------*
| json_data |
+----------------------+
| [{"a":10,"b":"foo"}] |
*----------------------*/
SELECT JSON_ARRAY(10, ['foo', 'bar'], [20, 30]) AS json_data
/*----------------------------*
| json_data |
+----------------------------+
| [10,["foo","bar"],[20,30]] |
*----------------------------*/
SELECT JSON_ARRAY(10, [JSON '20', JSON '"foo"']) AS json_data
/*-----------------*
| json_data |
+-----------------+
| [10,[20,"foo"]] |
*-----------------*/
You can create an empty JSON array. For example:
SELECT JSON_ARRAY() AS json_data
/*-----------*
| json_data |
+-----------+
| [] |
*-----------*/
JSON_OBJECT
- Signature 1:
JSON_OBJECT([json_key, json_value][, ...])
- Signature 2:
JSON_OBJECT(json_key_array, json_value_array)
Signature 1
JSON_OBJECT([json_key, json_value][, ...])
Description
Creates a JSON object, using key-value pairs.
Arguments:
json_key
: ASTRING
value that represents a key.json_value
: A JSON encoding-supported value.
Details:
- If two keys are passed in with the same name, only the first key-value pair is preserved.
- The order of key-value pairs is not preserved.
- If
json_key
isNULL
, an error is produced.
Return type
JSON
Examples
You can create an empty JSON object by passing in no JSON keys and values. For example:
SELECT JSON_OBJECT() AS json_data
/*-----------*
| json_data |
+-----------+
| {} |
*-----------*/
You can create a JSON object by passing in key-value pairs. For example:
SELECT JSON_OBJECT('foo', 10, 'bar', TRUE) AS json_data
/*-----------------------*
| json_data |
+-----------------------+
| {"bar":true,"foo":10} |
*-----------------------*/
SELECT JSON_OBJECT('foo', 10, 'bar', ['a', 'b']) AS json_data
/*----------------------------*
| json_data |
+----------------------------+
| {"bar":["a","b"],"foo":10} |
*----------------------------*/
SELECT JSON_OBJECT('a', NULL, 'b', JSON 'null') AS json_data
/*---------------------*
| json_data |
+---------------------+
| {"a":null,"b":null} |
*---------------------*/
SELECT JSON_OBJECT('a', 10, 'a', 'foo') AS json_data
/*-----------*
| json_data |
+-----------+
| {"a":10} |
*-----------*/
WITH Items AS (SELECT 'hello' AS key, 'world' AS value)
SELECT JSON_OBJECT(key, value) AS json_data FROM Items
/*-------------------*
| json_data |
+-------------------+
| {"hello":"world"} |
*-------------------*/
An error is produced if a SQL NULL
is passed in for a JSON key.
-- Error: A key cannot be NULL.
SELECT JSON_OBJECT(NULL, 1) AS json_data
An error is produced if the number of JSON keys and JSON values don't match:
-- Error: No matching signature for function JSON_OBJECT for argument types:
-- STRING, INT64, STRING
SELECT JSON_OBJECT('a', 1, 'b') AS json_data
Signature 2
JSON_OBJECT(json_key_array, json_value_array)
Creates a JSON object, using an array of keys and values.
Arguments:
json_key_array
: An array of zero or moreSTRING
keys.json_value_array
: An array of zero or more JSON encoding-supported values.
Details:
- If two keys are passed in with the same name, only the first key-value pair is preserved.
- The order of key-value pairs is not preserved.
- The number of keys must match the number of values, otherwise an error is produced.
- If any argument is
NULL
, an error is produced. - If a key in
json_key_array
isNULL
, an error is produced.
Return type
JSON
Examples
You can create an empty JSON object by passing in an empty array of keys and values. For example:
SELECT JSON_OBJECT(CAST([] AS ARRAY<STRING>), []) AS json_data
/*-----------*
| json_data |
+-----------+
| {} |
*-----------*/
You can create a JSON object by passing in an array of keys and an array of values. For example:
SELECT JSON_OBJECT(['a', 'b'], [10, NULL]) AS json_data
/*-------------------*
| json_data |
+-------------------+
| {"a":10,"b":null} |
*-------------------*/
SELECT JSON_OBJECT(['a', 'b'], [JSON '10', JSON '"foo"']) AS json_data
/*--------------------*
| json_data |
+--------------------+
| {"a":10,"b":"foo"} |
*--------------------*/
SELECT
JSON_OBJECT(
['a', 'b'],
[STRUCT(10 AS id, 'Red' AS color), STRUCT(20 AS id, 'Blue' AS color)])
AS json_data
/*------------------------------------------------------------*
| json_data |
+------------------------------------------------------------+
| {"a":{"color":"Red","id":10},"b":{"color":"Blue","id":20}} |
*------------------------------------------------------------*/
SELECT
JSON_OBJECT(
['a', 'b'],
[TO_JSON(10), TO_JSON(['foo', 'bar'])])
AS json_data
/*----------------------------*
| json_data |
+----------------------------+
| {"a":10,"b":["foo","bar"]} |
*----------------------------*/
The following query groups by id
and then creates an array of keys and
values from the rows with the same id
:
WITH
Fruits AS (
SELECT 0 AS id, 'color' AS json_key, 'red' AS json_value UNION ALL
SELECT 0, 'fruit', 'apple' UNION ALL
SELECT 1, 'fruit', 'banana' UNION ALL
SELECT 1, 'ripe', 'true'
)
SELECT JSON_OBJECT(ARRAY_AGG(json_key), ARRAY_AGG(json_value)) AS json_data
FROM Fruits
GROUP BY id
/*----------------------------------*
| json_data |
+----------------------------------+
| {"color":"red","fruit":"apple"} |
| {"fruit":"banana","ripe":"true"} |
*----------------------------------*/
An error is produced if the size of the JSON keys and values arrays don't match:
-- Error: The number of keys and values must match.
SELECT JSON_OBJECT(['a', 'b'], [10]) AS json_data
An error is produced if the array of JSON keys or JSON values is a SQL NULL
.
-- Error: The keys array cannot be NULL.
SELECT JSON_OBJECT(CAST(NULL AS ARRAY<STRING>), [10, 20]) AS json_data
-- Error: The values array cannot be NULL.
SELECT JSON_OBJECT(['a', 'b'], CAST(NULL AS ARRAY<INT64>)) AS json_data
JSON_QUERY
JSON_QUERY(json_string_expr, json_path)
JSON_QUERY(json_expr, json_path)
Description
Extracts a JSON value and converts it to a SQL
JSON-formatted STRING
or
JSON
value.
This function uses double quotes to escape invalid
JSONPath characters in JSON keys. For example: "a.b"
.
Arguments:
json_string_expr
: A JSON-formatted string. For example:'{"class": {"students": [{"name": "Jane"}]}}'
Extracts a SQL
NULL
when a JSON-formatted stringnull
is encountered. For example:SELECT JSON_QUERY("null", "$") -- Returns a SQL NULL
json_expr
: JSON. For example:JSON '{"class": {"students": [{"name": "Jane"}]}}'
Extracts a JSON
null
when a JSONnull
is encountered.SELECT JSON_QUERY(JSON 'null', "$") -- Returns a JSON 'null'
json_path
: The JSONPath. This identifies the data that you want to obtain from the input.
There are differences between the JSON-formatted string and JSON input types. For details, see Differences between the JSON and JSON-formatted STRING types.
Return type
json_string_expr
: A JSON-formattedSTRING
json_expr
:JSON
Examples
In the following example, JSON data is extracted and returned as JSON.
SELECT
JSON_QUERY(
JSON '{"class": {"students": [{"id": 5}, {"id": 12}]}}',
'$.class') AS json_data;
/*-----------------------------------*
| json_data |
+-----------------------------------+
| {"students":[{"id":5},{"id":12}]} |
*-----------------------------------*/
In the following examples, JSON data is extracted and returned as JSON-formatted strings.
SELECT
JSON_QUERY('{"class": {"students": [{"name": "Jane"}]}}', '$') AS json_text_string;
/*-----------------------------------------------------------*
| json_text_string |
+-----------------------------------------------------------+
| {"class":{"students":[{"name":"Jane"}]}} |
*-----------------------------------------------------------*/
SELECT JSON_QUERY('{"class": {"students": []}}', '$') AS json_text_string;
/*-----------------------------------------------------------*
| json_text_string |
+-----------------------------------------------------------+
| {"class":{"students":[]}} |
*-----------------------------------------------------------*/
SELECT
JSON_QUERY(
'{"class": {"students": [{"name": "John"},{"name": "Jamie"}]}}',
'$') AS json_text_string;
/*-----------------------------------------------------------*
| json_text_string |
+-----------------------------------------------------------+
| {"class":{"students":[{"name":"John"},{"name":"Jamie"}]}} |
*-----------------------------------------------------------*/
SELECT
JSON_QUERY(
'{"class": {"students": [{"name": "Jane"}]}}',
'$.class.students[0]') AS first_student;
/*-----------------*
| first_student |
+-----------------+
| {"name":"Jane"} |
*-----------------*/
SELECT
JSON_QUERY('{"class": {"students": []}}', '$.class.students[0]') AS first_student;
/*-----------------*
| first_student |
+-----------------+
| NULL |
*-----------------*/
SELECT
JSON_QUERY(
'{"class": {"students": [{"name": "John"}, {"name": "Jamie"}]}}',
'$.class.students[0]') AS first_student;
/*-----------------*
| first_student |
+-----------------+
| {"name":"John"} |
*-----------------*/
SELECT
JSON_QUERY(
'{"class": {"students": [{"name": "Jane"}]}}',
'$.class.students[1].name') AS second_student;
/*----------------*
| second_student |
+----------------+
| NULL |
*----------------*/
SELECT
JSON_QUERY(
'{"class": {"students": []}}',
'$.class.students[1].name') AS second_student;
/*----------------*
| second_student |
+----------------+
| NULL |
*----------------*/
SELECT
JSON_QUERY(
'{"class": {"students": [{"name": "John"}, {"name": null}]}}',
'$.class.students[1].name') AS second_student;
/*----------------*
| second_student |
+----------------+
| NULL |
*----------------*/
SELECT
JSON_QUERY(
'{"class": {"students": [{"name": "John"}, {"name": "Jamie"}]}}',
'$.class.students[1].name') AS second_student;
/*----------------*
| second_student |
+----------------+
| "Jamie" |
*----------------*/
SELECT
JSON_QUERY(
'{"class": {"students": [{"name": "Jane"}]}}',
'$.class."students"') AS student_names;
/*------------------------------------*
| student_names |
+------------------------------------+
| [{"name":"Jane"}] |
*------------------------------------*/
SELECT
JSON_QUERY(
'{"class": {"students": []}}',
'$.class."students"') AS student_names;
/*------------------------------------*
| student_names |
+------------------------------------+
| [] |
*------------------------------------*/
SELECT
JSON_QUERY(
'{"class": {"students": [{"name": "John"}, {"name": "Jamie"}]}}',
'$.class."students"') AS student_names;
/*------------------------------------*
| student_names |
+------------------------------------+
| [{"name":"John"},{"name":"Jamie"}] |
*------------------------------------*/
SELECT JSON_QUERY('{"a": null}', "$.a"); -- Returns a SQL NULL
SELECT JSON_QUERY('{"a": null}', "$.b"); -- Returns a SQL NULL
SELECT JSON_QUERY(JSON '{"a": null}', "$.a"); -- Returns a JSON 'null'
SELECT JSON_QUERY(JSON '{"a": null}', "$.b"); -- Returns a SQL NULL
JSON_QUERY_ARRAY
JSON_QUERY_ARRAY(json_string_expr[, json_path])
JSON_QUERY_ARRAY(json_expr[, json_path])
Description
Extracts a JSON array and converts it to
a SQL ARRAY<JSON-formatted STRING>
or
ARRAY<JSON>
value.
In addition, this function uses double quotes to escape invalid
JSONPath characters in JSON keys. For example: "a.b"
.
Arguments:
json_string_expr
: A JSON-formatted string. For example:'["a", "b", {"key": "c"}]'
json_expr
: JSON. For example:JSON '["a", "b", {"key": "c"}]'
json_path
: The JSONPath. This identifies the data that you want to obtain from the input. If this optional parameter is not provided, then the JSONPath$
symbol is applied, which means that all of the data is analyzed.
There are differences between the JSON-formatted string and JSON input types. For details, see Differences between the JSON and JSON-formatted STRING types.
Return type
json_string_expr
:ARRAY<JSON-formatted STRING>
json_expr
:ARRAY<JSON>
Examples
This extracts items in JSON to an array of JSON
values:
SELECT JSON_QUERY_ARRAY(
JSON '{"fruits": ["apples", "oranges", "grapes"]}', '$.fruits'
) AS json_array;
/*---------------------------------*
| json_array |
+---------------------------------+
| ["apples", "oranges", "grapes"] |
*---------------------------------*/
This extracts the items in a JSON-formatted string to a string array:
SELECT JSON_QUERY_ARRAY('[1, 2, 3]') AS string_array;
/*--------------*
| string_array |
+--------------+
| [1, 2, 3] |
*--------------*/
This extracts a string array and converts it to an integer array:
SELECT ARRAY(
SELECT CAST(integer_element AS INT64)
FROM UNNEST(
JSON_QUERY_ARRAY('[1, 2, 3]','$')
) AS integer_element
) AS integer_array;
/*---------------*
| integer_array |
+---------------+
| [1, 2, 3] |
*---------------*/
This extracts string values in a JSON-formatted string to an array:
-- Doesn't strip the double quotes
SELECT JSON_QUERY_ARRAY('["apples", "oranges", "grapes"]', '$') AS string_array;
/*---------------------------------*
| string_array |
+---------------------------------+
| ["apples", "oranges", "grapes"] |
*---------------------------------*/
-- Strips the double quotes
SELECT ARRAY(
SELECT JSON_VALUE(string_element, '$')
FROM UNNEST(JSON_QUERY_ARRAY('["apples", "oranges", "grapes"]', '$')) AS string_element
) AS string_array;
/*---------------------------*
| string_array |
+---------------------------+
| [apples, oranges, grapes] |
*---------------------------*/
This extracts only the items in the fruit
property to an array:
SELECT JSON_QUERY_ARRAY(
'{"fruit": [{"apples": 5, "oranges": 10}, {"apples": 2, "oranges": 4}], "vegetables": [{"lettuce": 7, "kale": 8}]}',
'$.fruit'
) AS string_array;
/*-------------------------------------------------------*
| string_array |
+-------------------------------------------------------+
| [{"apples":5,"oranges":10}, {"apples":2,"oranges":4}] |
*-------------------------------------------------------*/
These are equivalent:
SELECT JSON_QUERY_ARRAY('{"fruits": ["apples", "oranges", "grapes"]}', '$.fruits') AS string_array;
SELECT JSON_QUERY_ARRAY('{"fruits": ["apples", "oranges", "grapes"]}', '$."fruits"') AS string_array;
-- The queries above produce the following result:
/*---------------------------------*
| string_array |
+---------------------------------+
| ["apples", "oranges", "grapes"] |
*---------------------------------*/
In cases where a JSON key uses invalid JSONPath characters, you can escape those
characters using double quotes: " "
. For example:
SELECT JSON_QUERY_ARRAY('{"a.b": {"c": ["world"]}}', '$."a.b".c') AS hello;
/*-----------*
| hello |
+-----------+
| ["world"] |
*-----------*/
The following examples show how invalid requests and empty arrays are handled:
-- An error is returned if you provide an invalid JSONPath.
SELECT JSON_QUERY_ARRAY('["foo", "bar", "baz"]', 'INVALID_JSONPath') AS result;
-- If the JSONPath does not refer to an array, then NULL is returned.
SELECT JSON_QUERY_ARRAY('{"a": "foo"}', '$.a') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
-- If a key that does not exist is specified, then the result is NULL.
SELECT JSON_QUERY_ARRAY('{"a": "foo"}', '$.b') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
-- Empty arrays in JSON-formatted strings are supported.
SELECT JSON_QUERY_ARRAY('{"a": "foo", "b": []}', '$.b') AS result;
/*--------*
| result |
+--------+
| [] |
*--------*/
JSON_TYPE
JSON_TYPE(json_expr)
Description
Gets the JSON type of the outermost JSON value and converts the name of
this type to a SQL STRING
value. The names of these JSON types can be
returned: object
, array
, string
, number
, boolean
, null
Arguments:
json_expr
: JSON. For example:JSON '{"name": "sky", "color": "blue"}'
If this expression is SQL
NULL
, the function returns SQLNULL
. If the extracted JSON value is not a valid JSON type, an error is produced.
Return type
STRING
Examples
SELECT json_val, JSON_TYPE(json_val) AS type
FROM
UNNEST(
[
JSON '"apple"',
JSON '10',
JSON '3.14',
JSON 'null',
JSON '{"city": "New York", "State": "NY"}',
JSON '["apple", "banana"]',
JSON 'false'
]
) AS json_val;
/*----------------------------------+---------*
| json_val | type |
+----------------------------------+---------+
| "apple" | string |
| 10 | number |
| 3.14 | number |
| null | null |
| {"State":"NY","city":"New York"} | object |
| ["apple","banana"] | array |
| false | boolean |
*----------------------------------+---------*/
JSON_VALUE
JSON_VALUE(json_string_expr[, json_path])
JSON_VALUE(json_expr[, json_path])
Description
Extracts a JSON scalar value and converts it to a SQL STRING
value.
In addition, this function:
- Removes the outermost quotes and unescapes the values.
- Returns a SQL
NULL
if a non-scalar value is selected. - Uses double quotes to escape invalid JSONPath characters
in JSON keys. For example:
"a.b"
.
Arguments:
json_string_expr
: A JSON-formatted string. For example:'{"name": "Jakob", "age": "6"}'
json_expr
: JSON. For example:JSON '{"name": "Jane", "age": "6"}'
json_path
: The JSONPath. This identifies the data that you want to obtain from the input. If this optional parameter is not provided, then the JSONPath$
symbol is applied, which means that all of the data is analyzed.If
json_path
returns a JSONnull
or a non-scalar value (in other words, ifjson_path
refers to an object or an array), then a SQLNULL
is returned.
There are differences between the JSON-formatted string and JSON input types. For details, see Differences between the JSON and JSON-formatted STRING types.
Return type
STRING
Examples
In the following example, JSON data is extracted and returned as a scalar value.
SELECT JSON_VALUE(JSON '{"name": "Jakob", "age": "6" }', '$.age') AS scalar_age;
/*------------*
| scalar_age |
+------------+
| 6 |
*------------*/
The following example compares how results are returned for the JSON_QUERY
and JSON_VALUE
functions.
SELECT JSON_QUERY('{"name": "Jakob", "age": "6"}', '$.name') AS json_name,
JSON_VALUE('{"name": "Jakob", "age": "6"}', '$.name') AS scalar_name,
JSON_QUERY('{"name": "Jakob", "age": "6"}', '$.age') AS json_age,
JSON_VALUE('{"name": "Jakob", "age": "6"}', '$.age') AS scalar_age;
/*-----------+-------------+----------+------------*
| json_name | scalar_name | json_age | scalar_age |
+-----------+-------------+----------+------------+
| "Jakob" | Jakob | "6" | 6 |
*-----------+-------------+----------+------------*/
SELECT JSON_QUERY('{"fruits": ["apple", "banana"]}', '$.fruits') AS json_query,
JSON_VALUE('{"fruits": ["apple", "banana"]}', '$.fruits') AS json_value;
/*--------------------+------------*
| json_query | json_value |
+--------------------+------------+
| ["apple","banana"] | NULL |
*--------------------+------------*/
In cases where a JSON key uses invalid JSONPath characters, you can escape those characters using double quotes. For example:
SELECT JSON_VALUE('{"a.b": {"c": "world"}}', '$."a.b".c') AS hello;
/*-------*
| hello |
+-------+
| world |
*-------*/
JSON_VALUE_ARRAY
JSON_VALUE_ARRAY(json_string_expr[, json_path])
JSON_VALUE_ARRAY(json_expr[, json_path])
Description
Extracts a JSON array of scalar values and converts it to a SQL
ARRAY<STRING>
value.
In addition, this function:
- Removes the outermost quotes and unescapes the values.
- Returns a SQL
NULL
if the selected value is not an array or not an array containing only scalar values. - Uses double quotes to escape invalid JSONPath characters
in JSON keys. For example:
"a.b"
.
Arguments:
json_string_expr
: A JSON-formatted string. For example:'["apples", "oranges", "grapes"]'
json_expr
: JSON. For example:JSON '["apples", "oranges", "grapes"]'
json_path
: The JSONPath. This identifies the data that you want to obtain from the input. If this optional parameter is not provided, then the JSONPath$
symbol is applied, which means that all of the data is analyzed.
There are differences between the JSON-formatted string and JSON input types. For details, see Differences between the JSON and JSON-formatted STRING types.
Caveats:
- A JSON
null
in the input array produces a SQLNULL
as the output for that JSONnull
. - If a JSONPath matches an array that contains scalar objects and a JSON
null
, then the output is an array of the scalar objects and a SQLNULL
.
Return type
ARRAY<STRING>
Examples
This extracts items in JSON to a string array:
SELECT JSON_VALUE_ARRAY(
JSON '{"fruits": ["apples", "oranges", "grapes"]}', '$.fruits'
) AS string_array;
/*---------------------------*
| string_array |
+---------------------------+
| [apples, oranges, grapes] |
*---------------------------*/
The following example compares how results are returned for the
JSON_QUERY_ARRAY
and JSON_VALUE_ARRAY
functions.
SELECT JSON_QUERY_ARRAY('["apples", "oranges"]') AS json_array,
JSON_VALUE_ARRAY('["apples", "oranges"]') AS string_array;
/*-----------------------+-------------------*
| json_array | string_array |
+-----------------------+-------------------+
| ["apples", "oranges"] | [apples, oranges] |
*-----------------------+-------------------*/
This extracts the items in a JSON-formatted string to a string array:
-- Strips the double quotes
SELECT JSON_VALUE_ARRAY('["foo", "bar", "baz"]', '$') AS string_array;
/*-----------------*
| string_array |
+-----------------+
| [foo, bar, baz] |
*-----------------*/
This extracts a string array and converts it to an integer array:
SELECT ARRAY(
SELECT CAST(integer_element AS INT64)
FROM UNNEST(
JSON_VALUE_ARRAY('[1, 2, 3]', '$')
) AS integer_element
) AS integer_array;
/*---------------*
| integer_array |
+---------------+
| [1, 2, 3] |
*---------------*/
These are equivalent:
SELECT JSON_VALUE_ARRAY('{"fruits": ["apples", "oranges", "grapes"]}', '$.fruits') AS string_array;
SELECT JSON_VALUE_ARRAY('{"fruits": ["apples", "oranges", "grapes"]}', '$."fruits"') AS string_array;
-- The queries above produce the following result:
/*---------------------------*
| string_array |
+---------------------------+
| [apples, oranges, grapes] |
*---------------------------*/
In cases where a JSON key uses invalid JSONPath characters, you can escape those
characters using double quotes: " "
. For example:
SELECT JSON_VALUE_ARRAY('{"a.b": {"c": ["world"]}}', '$."a.b".c') AS hello;
/*---------*
| hello |
+---------+
| [world] |
*---------*/
The following examples explore how invalid requests and empty arrays are handled:
-- An error is thrown if you provide an invalid JSONPath.
SELECT JSON_VALUE_ARRAY('["foo", "bar", "baz"]', 'INVALID_JSONPath') AS result;
-- If the JSON-formatted string is invalid, then NULL is returned.
SELECT JSON_VALUE_ARRAY('}}', '$') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
-- If the JSON document is NULL, then NULL is returned.
SELECT JSON_VALUE_ARRAY(NULL, '$') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
-- If a JSONPath does not match anything, then the output is NULL.
SELECT JSON_VALUE_ARRAY('{"a": ["foo", "bar", "baz"]}', '$.b') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
-- If a JSONPath matches an object that is not an array, then the output is NULL.
SELECT JSON_VALUE_ARRAY('{"a": "foo"}', '$') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
-- If a JSONPath matches an array of non-scalar objects, then the output is NULL.
SELECT JSON_VALUE_ARRAY('{"a": [{"b": "foo", "c": 1}, {"b": "bar", "c": 2}], "d": "baz"}', '$.a') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
-- If a JSONPath matches an array of mixed scalar and non-scalar objects,
-- then the output is NULL.
SELECT JSON_VALUE_ARRAY('{"a": [10, {"b": 20}]', '$.a') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
-- If a JSONPath matches an empty JSON array, then the output is an empty array instead of NULL.
SELECT JSON_VALUE_ARRAY('{"a": "foo", "b": []}', '$.b') AS result;
/*--------*
| result |
+--------+
| [] |
*--------*/
-- In the following query, the JSON null input is returned as a
-- SQL NULL in the output.
SELECT JSON_VALUE_ARRAY('["world", null, 1]') AS result;
/*------------------*
| result |
+------------------+
| [world, NULL, 1] |
*------------------*/
LAX_BOOL
LAX_BOOL(json_expr)
Description
Attempts to convert a JSON value to a SQL BOOL
value.
Arguments:
json_expr
: JSON. For example:JSON 'true'
Details:
- If
json_expr
is SQLNULL
, the function returns SQLNULL
. - See the conversion rules in the next section for additional
NULL
handling.
Conversion rules
From JSON type | To SQL BOOL |
---|---|
boolean |
If the JSON boolean is true , returns TRUE .
Otherwise, returns FALSE .
|
string |
If the JSON string is 'true' , returns TRUE .
If the JSON string is 'false' , returns FALSE .
If the JSON string is any other value or has whitespace in it,
returns NULL .
This conversion is case-insensitive.
|
number |
If the JSON number is a representation of 0 ,
returns FALSE . Otherwise, returns TRUE .
|
other type or null | NULL |
Return type
BOOL
Examples
Example with input that is a JSON boolean:
SELECT LAX_BOOL(JSON 'true') AS result;
/*--------*
| result |
+--------+
| true |
*--------*/
Examples with inputs that are JSON strings:
SELECT LAX_BOOL(JSON '"true"') AS result;
/*--------*
| result |
+--------+
| TRUE |
*--------*/
SELECT LAX_BOOL(JSON '"true "') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
SELECT LAX_BOOL(JSON '"foo"') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
Examples with inputs that are JSON numbers:
SELECT LAX_BOOL(JSON '10') AS result;
/*--------*
| result |
+--------+
| TRUE |
*--------*/
SELECT LAX_BOOL(JSON '0') AS result;
/*--------*
| result |
+--------+
| FALSE |
*--------*/
SELECT LAX_BOOL(JSON '0.0') AS result;
/*--------*
| result |
+--------+
| FALSE |
*--------*/
SELECT LAX_BOOL(JSON '-1.1') AS result;
/*--------*
| result |
+--------+
| TRUE |
*--------*/
LAX_FLOAT64
LAX_FLOAT64(json_expr)
Description
Attempts to convert a JSON value to a
SQL FLOAT64
value.
Arguments:
json_expr
: JSON. For example:JSON '9.8'
Details:
- If
json_expr
is SQLNULL
, the function returns SQLNULL
. - See the conversion rules in the next section for additional
NULL
handling.
Conversion rules
From JSON type | To SQL FLOAT64 |
---|---|
boolean |
NULL
|
string |
If the JSON string represents a JSON number, parses it as
a
JSON number, and then safe casts the result as a
FLOAT64 value.
If the JSON string can't be converted, returns NULL .
|
number |
Casts the JSON number as a
FLOAT64 value.
Large JSON numbers are rounded.
|
other type or null | NULL |
Return type
FLOAT64
Examples
Examples with inputs that are JSON numbers:
SELECT LAX_FLOAT64(JSON '9.8') AS result;
/*--------*
| result |
+--------+
| 9.8 |
*--------*/
SELECT LAX_FLOAT64(JSON '9') AS result;
/*--------*
| result |
+--------+
| 9.0 |
*--------*/
SELECT LAX_FLOAT64(JSON '9007199254740993') AS result;
/*--------------------*
| result |
+--------------------+
| 9007199254740992.0 |
*--------------------*/
SELECT LAX_FLOAT64(JSON '1e100') AS result;
/*--------*
| result |
+--------+
| 1e+100 |
*--------*/
Examples with inputs that are JSON booleans:
SELECT LAX_FLOAT64(JSON 'true') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
SELECT LAX_FLOAT64(JSON 'false') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
Examples with inputs that are JSON strings:
SELECT LAX_FLOAT64(JSON '"10"') AS result;
/*--------*
| result |
+--------+
| 10.0 |
*--------*/
SELECT LAX_FLOAT64(JSON '"1.1"') AS result;
/*--------*
| result |
+--------+
| 1.1 |
*--------*/
SELECT LAX_FLOAT64(JSON '"1.1e2"') AS result;
/*--------*
| result |
+--------+
| 110.0 |
*--------*/
SELECT LAX_FLOAT64(JSON '"9007199254740993"') AS result;
/*--------------------*
| result |
+--------------------+
| 9007199254740992.0 |
*--------------------*/
SELECT LAX_FLOAT64(JSON '"+1.5"') AS result;
/*--------*
| result |
+--------+
| 1.5 |
*--------*/
SELECT LAX_FLOAT64(JSON '"NaN"') AS result;
/*--------*
| result |
+--------+
| NaN |
*--------*/
SELECT LAX_FLOAT64(JSON '"Inf"') AS result;
/*----------*
| result |
+----------+
| Infinity |
*----------*/
SELECT LAX_FLOAT64(JSON '"-InfiNiTY"') AS result;
/*-----------*
| result |
+-----------+
| -Infinity |
*-----------*/
SELECT LAX_FLOAT64(JSON '"foo"') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
LAX_INT64
LAX_INT64(json_expr)
Description
Attempts to convert a JSON value to a SQL INT64
value.
Arguments:
json_expr
: JSON. For example:JSON '999'
Details:
- If
json_expr
is SQLNULL
, the function returns SQLNULL
. - See the conversion rules in the next section for additional
NULL
handling.
Conversion rules
From JSON type | To SQL INT64 |
---|---|
boolean |
If the JSON boolean is true , returns 1 .
If false , returns 0 .
|
string |
If the JSON string represents a JSON number, parses it as
a
JSON number, and then safe casts the results as an
INT64 value.
If the JSON string can't be converted, returns NULL .
|
number |
Casts the JSON number as an INT64 value.
If the JSON number can't be converted, returns NULL .
|
other type or null | NULL |
Return type
INT64
Examples
Examples with inputs that are JSON numbers:
SELECT LAX_INT64(JSON '10') AS result;
/*--------*
| result |
+--------+
| 10 |
*--------*/
SELECT LAX_INT64(JSON '10.0') AS result;
/*--------*
| result |
+--------+
| 10 |
*--------*/
SELECT LAX_INT64(JSON '1.1') AS result;
/*--------*
| result |
+--------+
| 1 |
*--------*/
SELECT LAX_INT64(JSON '3.5') AS result;
/*--------*
| result |
+--------+
| 4 |
*--------*/
SELECT LAX_INT64(JSON '1.1e2') AS result;
/*--------*
| result |
+--------+
| 110 |
*--------*/
SELECT LAX_INT64(JSON '1e100') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
Examples with inputs that are JSON booleans:
SELECT LAX_INT64(JSON 'true') AS result;
/*--------*
| result |
+--------+
| 1 |
*--------*/
SELECT LAX_INT64(JSON 'false') AS result;
/*--------*
| result |
+--------+
| 0 |
*--------*/
Examples with inputs that are JSON strings:
SELECT LAX_INT64(JSON '"10"') AS result;
/*--------*
| result |
+--------+
| 10 |
*--------*/
SELECT LAX_INT64(JSON '"1.1"') AS result;
/*--------*
| result |
+--------+
| 1 |
*--------*/
SELECT LAX_INT64(JSON '"1.1e2"') AS result;
/*--------*
| result |
+--------+
| 110 |
*--------*/
SELECT LAX_INT64(JSON '"+1.5"') AS result;
/*--------*
| result |
+--------+
| 2 |
*--------*/
SELECT LAX_INT64(JSON '"1e100"') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
SELECT LAX_INT64(JSON '"foo"') AS result;
/*--------*
| result |
+--------+
| NULL |
*--------*/
LAX_STRING
LAX_STRING(json_expr)
Description
Attempts to convert a JSON value to a SQL STRING
value.
Arguments:
json_expr
: JSON. For example:JSON '"name"'
Details:
- If
json_expr
is SQLNULL
, the function returns SQLNULL
. - See the conversion rules in the next section for additional
NULL
handling.
Conversion rules
From JSON type | To SQL STRING |
---|---|
boolean |
If the JSON boolean is true , returns 'true' .
If false , returns 'false' .
|
string |
Returns the JSON string as a STRING value.
|
number |
Returns the JSON number as a STRING value.
|
other type or null | NULL |
Return type
STRING
Examples
Examples with inputs that are JSON strings:
SELECT LAX_STRING(JSON '"purple"') AS result;
/*--------*
| result |
+--------+
| purple |
*--------*/
SELECT LAX_STRING(JSON '"10"') AS result;
/*--------*
| result |
+--------+
| 10 |
*--------*/
Examples with inputs that are JSON booleans:
SELECT LAX_STRING(JSON 'true') AS result;
/*--------*
| result |
+--------+
| true |
*--------*/
SELECT LAX_STRING(JSON 'false') AS result;
/*--------*
| result |
+--------+
| false |
*--------*/
Examples with inputs that are JSON numbers:
SELECT LAX_STRING(JSON '10.0') AS result;
/*--------*
| result |
+--------+
| 10 |
*--------*/
SELECT LAX_STRING(JSON '10') AS result;
/*--------*
| result |
+--------+
| 10 |
*--------*/
SELECT LAX_STRING(JSON '1e100') AS result;
/*--------*
| result |
+--------+
| 1e+100 |
*--------*/
PARSE_JSON
PARSE_JSON(
json_string_expr
[, wide_number_mode => { 'exact' | 'round' } ]
)
Description
Converts a JSON-formatted STRING
value to a JSON
value.
Arguments:
json_string_expr
: A JSON-formatted string. For example:'{"class": {"students": [{"name": "Jane"}]}}'
wide_number_mode
: A named argument with aSTRING
value. Determines how to handle numbers that can't be stored in aJSON
value without the loss of precision. If used,wide_number_mode
must include one of the following values:exact
(default): Only accept numbers that can be stored without loss of precision. If a number that cannot be stored without loss of precision is encountered, the function throws an error.round
: If a number that cannot be stored without loss of precision is encountered, attempt to round it to a number that can be stored without loss of precision. If the number cannot be rounded, the function throws an error.
If a number appears in a JSON object or array, the
wide_number_mode
argument is applied to the number in the object or array.
Numbers from the following domains can be stored in JSON without loss of precision:
- 64-bit signed/unsigned integers, such as
INT64
FLOAT64
Return type
JSON
Examples
In the following example, a JSON-formatted string is converted to JSON
.
SELECT PARSE_JSON('{"coordinates": [10, 20], "id": 1}') AS json_data;
/*--------------------------------*
| json_data |
+--------------------------------+
| {"coordinates":[10,20],"id":1} |
*--------------------------------*/
The following queries fail because:
- The number that was passed in cannot be stored without loss of precision.
wide_number_mode=>'exact'
is used implicitly in the first query and explicitly in the second query.
SELECT PARSE_JSON('{"id": 922337203685477580701}') AS json_data; -- fails
SELECT PARSE_JSON('{"id": 922337203685477580701}', wide_number_mode=>'exact') AS json_data; -- fails
The following query rounds the number to a number that can be stored in JSON.
SELECT PARSE_JSON('{"id": 922337203685477580701}', wide_number_mode=>'round') AS json_data;
/*------------------------------*
| json_data |
+------------------------------+
| {"id":9.223372036854776e+20} |
*------------------------------*/
You can also use valid JSON-formatted strings that don't represent name/value pairs. For example:
SELECT PARSE_JSON('6') AS json_data;
/*------------------------------*
| json_data |
+------------------------------+
| 6 |
*------------------------------*/
SELECT PARSE_JSON('"red"') AS json_data;
/*------------------------------*
| json_data |
+------------------------------+
| "red" |
*------------------------------*/
STRING
STRING(json_expr)
Description
Converts a JSON string to a SQL STRING
value.
Arguments:
json_expr
: JSON. For example:JSON '"purple"'
If the JSON value is not a string, an error is produced. If the expression is SQL
NULL
, the function returns SQLNULL
.
Return type
STRING
Examples
SELECT STRING(JSON '"purple"') AS color;
/*--------*
| color |
+--------+
| purple |
*--------*/
SELECT STRING(JSON_QUERY(JSON '{"name": "sky", "color": "blue"}', "$.color")) AS color;
/*-------*
| color |
+-------+
| blue |
*-------*/
The following examples show how invalid requests are handled:
-- An error is thrown if the JSON is not of type string.
SELECT STRING(JSON '123') AS result; -- Throws an error
SELECT STRING(JSON 'null') AS result; -- Throws an error
SELECT SAFE.STRING(JSON '123') AS result; -- Returns a SQL NULL
STRING_ARRAY
STRING_ARRAY(json_expr)
Description
Converts a JSON array of strings to a SQL ARRAY<STRING>
value.
Arguments:
json_expr
: JSON. For example:JSON '["purple", "blue"]'
If the JSON value is not an array of strings, an error is produced. If the expression is SQL
NULL
, the function returns SQLNULL
.
Return type
ARRAY<STRING>
Examples
SELECT STRING_ARRAY(JSON '["purple", "blue"]') AS colors;
/*----------------*
| colors |
+----------------+
| [purple, blue] |
*----------------*/
The following examples show how invalid requests are handled:
-- An error is thrown if the JSON is not an array of strings.
SELECT STRING_ARRAY(JSON '[123]') AS result; -- Throws an error
SELECT STRING_ARRAY(JSON '[null]') AS result; -- Throws an error
SELECT STRING_ARRAY(JSON 'null') AS result; -- Throws an error
TO_JSON
TO_JSON(
sql_value
[, stringify_wide_numbers => { TRUE | FALSE } ]
)
Description
Converts a SQL value to a JSON value.
Arguments:
sql_value
: The SQL value to convert to a JSON value. You can review the GoogleSQL data types that this function supports and their JSON encodings here.stringify_wide_numbers
: A named argument that's eitherTRUE
orFALSE
(default).- If
TRUE
, numeric values outside of theFLOAT64
type domain are encoded as strings. - If
FALSE
(default), numeric values outside of theFLOAT64
type domain are not encoded as strings, but are stored as JSON numbers. If a numerical value cannot be stored in JSON without loss of precision, an error is thrown.
The following numerical data types are affected by the
stringify_wide_numbers
argument:- If
INT64
NUMERIC
If one of these numerical data types appears in a container data type such as an
ARRAY
orSTRUCT
, thestringify_wide_numbers
argument is applied to the numerical data types in the container data type.
Return type
JSON
Examples
In the following example, the query converts rows in a table to JSON values.
With CoordinatesTable AS (
(SELECT 1 AS id, [10, 20] AS coordinates) UNION ALL
(SELECT 2 AS id, [30, 40] AS coordinates) UNION ALL
(SELECT 3 AS id, [50, 60] AS coordinates))
SELECT TO_JSON(t) AS json_objects
FROM CoordinatesTable AS t;
/*--------------------------------*
| json_objects |
+--------------------------------+
| {"coordinates":[10,20],"id":1} |
| {"coordinates":[30,40],"id":2} |
| {"coordinates":[50,60],"id":3} |
*--------------------------------*/
In the following example, the query returns a large numerical value as a JSON string.
SELECT TO_JSON(9007199254740993, stringify_wide_numbers=>TRUE) as stringify_on;
/*--------------------*
| stringify_on |
+--------------------+
| "9007199254740993" |
*--------------------*/
In the following example, both queries return a large numerical value as a JSON number.
SELECT TO_JSON(9007199254740993, stringify_wide_numbers=>FALSE) as stringify_off;
SELECT TO_JSON(9007199254740993) as stringify_off;
/*------------------*
| stringify_off |
+------------------+
| 9007199254740993 |
*------------------*/
In the following example, only large numeric values are converted to JSON strings.
With T1 AS (
(SELECT 9007199254740993 AS id) UNION ALL
(SELECT 2 AS id))
SELECT TO_JSON(t, stringify_wide_numbers=>TRUE) AS json_objects
FROM T1 AS t;
/*---------------------------*
| json_objects |
+---------------------------+
| {"id":"9007199254740993"} |
| {"id":2} |
*---------------------------*/
In this example, the values 9007199254740993
(INT64
)
and 2.1
(FLOAT64
) are converted
to the common supertype FLOAT64
, which is not
affected by the stringify_wide_numbers
argument.
With T1 AS (
(SELECT 9007199254740993 AS id) UNION ALL
(SELECT 2.1 AS id))
SELECT TO_JSON(t, stringify_wide_numbers=>TRUE) AS json_objects
FROM T1 AS t;
/*------------------------------*
| json_objects |
+------------------------------+
| {"id":9.007199254740992e+15} |
| {"id":2.1} |
*------------------------------*/
TO_JSON_STRING
TO_JSON_STRING(json_expr)
Description
Converts a JSON value to a SQL JSON-formatted STRING
value.
Arguments:
json_expr
: JSON. For example:JSON '{"class": {"students": [{"name": "Jane"}]}}'
Return type
A JSON-formatted STRING
Example
Convert a JSON value to a JSON-formatted STRING
value.
SELECT TO_JSON_STRING(JSON '{"id": 1, "coordinates": [10, 20]}') AS json_string
/*--------------------------------*
| json_string |
+--------------------------------+
| {"coordinates":[10,20],"id":1} |
*--------------------------------*/
JSON encodings
You can encode a SQL value as a JSON value with the following functions:
TO_JSON
JSON_ARRAY
(usesTO_JSON
encoding)JSON_OBJECT
(usesTO_JSON
encoding)
The following SQL to JSON encodings are supported:
From SQL | To JSON | Examples |
---|---|---|
NULL |
null |
SQL input: NULL JSON output: null
|
BOOL | boolean |
SQL input: TRUE JSON output: true SQL input: FALSE JSON output: false |
INT64 |
number or string
If the
If the |
SQL input: 9007199254740992 JSON output: 9007199254740992 SQL input: 9007199254740993 JSON output: 9007199254740993 SQL input with stringify_wide_numbers=>TRUE: 9007199254740992 JSON output: 9007199254740992 SQL input with stringify_wide_numbers=>TRUE: 9007199254740993 JSON output: "9007199254740993" |
NUMERIC |
number or string
If the |
SQL input: -1 JSON output: -1 SQL input: 0 JSON output: 0 SQL input: 9007199254740993 JSON output: 9007199254740993 SQL input: 123.56 JSON output: 123.56 SQL input with stringify_wide_numbers=>TRUE: 9007199254740993 JSON output: "9007199254740993" SQL input with stringify_wide_numbers=>TRUE: 123.56 JSON output: 123.56 |
FLOAT64 |
number or string
|
SQL input: 1.0 JSON output: 1 SQL input: 9007199254740993 JSON output: 9007199254740993 SQL input: "+inf" JSON output: "Infinity" SQL input: "-inf" JSON output: "-Infinity" SQL input: "NaN" JSON output: "NaN" |
STRING |
string
Encoded as a string, escaped according to the JSON standard.
Specifically, |
SQL input: "abc" JSON output: "abc" SQL input: "\"abc\"" JSON output: "\"abc\"" |
BYTES |
string Uses RFC 4648 Base64 data encoding. |
SQL input: b"Google" JSON output: "R29vZ2xl" |
ENUM |
string Invalid enum values are encoded as their number, such as 0 or 42. |
SQL input: Color.Red JSON output: "Red" |
DATE | string |
SQL input: DATE '2017-03-06' JSON output: "2017-03-06" |
TIMESTAMP |
string Encoded as ISO 8601 date and time, where T separates the date and time and Z (Zulu/UTC) represents the time zone. |
SQL input: TIMESTAMP '2017-03-06 12:34:56.789012' JSON output: "2017-03-06T12:34:56.789012Z" |
JSON |
data of the input JSON |
SQL input: JSON '{"item": "pen", "price": 10}' JSON output: {"item":"pen", "price":10} SQL input: [1, 2, 3] JSON output: [1, 2, 3] |
ARRAY |
array Can contain zero or more elements. |
SQL input: ["red", "blue", "green"] JSON output: ["red","blue","green"] SQL input: [1, 2, 3] JSON output: [1,2,3] |
STRUCT |
object The object can contain zero or more key-value pairs. Each value is formatted according to its type.
For
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,
|
SQL input: STRUCT(12 AS purchases, TRUE AS inStock) JSON output: {"inStock": true,"purchases":12} |
PROTO |
object The object can contain zero or more key-value pairs. Each value is formatted according to its type.
Field names with underscores are converted to camel case in accordance
with
protobuf json conversion. Field values are formatted according to
protobuf json conversion. If a
|
SQL input: NEW Item(12 AS purchases,TRUE AS in_Stock) JSON output: {"purchases":12,"inStock": true} |
GRAPH_ELEMENT |
object The object can contain zero or more key-value pairs. Each value is formatted according to its type.
For
|
SQL:
GRAPH FinGraph MATCH (p:Person WHERE p.name = 'Dana') RETURN TO_JSON(p) AS dana_json; JSON output (truncated): {"identifier":"ZGFuYQ==","kind":"node","labels":["Person"],"properties":{"id":2,"name":"Dana"}} |
JSONPath format
With the JSONPath format, you can identify the values you want to obtain from a JSON-formatted string.
If a key in a JSON functions contains a JSON format operator, refer to each JSON function for how to escape them.
A JSON function returns NULL
if the JSONPath format does not match a value in
a JSON-formatted string. If the selected value for a scalar function is not
scalar, such as an object or an array, the function returns NULL
. If the
JSONPath format is invalid, an error is produced.
Operators for JSONPath
The JSONPath format supports these operators:
Operator | Description | Examples |
---|---|---|
$ |
Root object or element. The JSONPath format must start with this operator, which refers to the outermost level of the JSON-formatted string. |
JSON-formatted string:
JSON path:
JSON result: |
. |
Child operator. You can identify child values using dot-notation. |
JSON-formatted string:
JSON path:
JSON result: |
[] |
Subscript operator. If the object is a JSON array, you can use brackets to specify the array index. |
JSON-formatted string:
JSON path:
JSON result: |
Differences between the JSON and JSON-formatted STRING types
Many JSON functions accept two input types:
JSON
typeSTRING
type
The STRING
version of the extraction functions behaves differently than the
JSON
version, mainly because JSON
type values are always validated whereas
JSON-formatted STRING
type values are not.
Non-validation of STRING
inputs
The following STRING
is invalid JSON because it is missing a trailing }
:
{"hello": "world"
The JSON function reads the input from the beginning and stops as soon as the field to extract is found, without reading the remainder of the input. A parsing error is not produced.
With the JSON
type, however, JSON '{"hello": "world"'
returns a parsing
error.
For example:
SELECT JSON_VALUE('{"hello": "world"', "$.hello") AS hello;
/*-------*
| hello |
+-------+
| world |
*-------*/
SELECT JSON_VALUE(JSON '{"hello": "world"', "$.hello") AS hello;
-- An error is returned: Invalid JSON literal: syntax error while parsing
-- object - unexpected end of input; expected '}'
No strict validation of extracted values
In the following examples, duplicated keys are not removed when using a
JSON-formatted string. Similarly, keys order is preserved. For the JSON
type, JSON '{"key": 1, "key": 2}'
will result in JSON '{"key":1}'
during
parsing.
SELECT JSON_QUERY('{"key": 1, "key": 2}', "$") AS string;
/*-------------------*
| string |
+-------------------+
| {"key":1,"key":2} |
*-------------------*/
SELECT JSON_QUERY(JSON '{"key": 1, "key": 2}', "$") AS json;
/*-----------*
| json |
+-----------+
| {"key":1} |
*-----------*/
JSON null
When using a JSON-formatted STRING
type in a JSON function, a JSON null
value is extracted as a SQL NULL
value.
When using a JSON type in a JSON function, a JSON null
value returns a JSON
null
value.
WITH t AS (
SELECT '{"name": null}' AS json_string, JSON '{"name": null}' AS json)
SELECT JSON_QUERY(json_string, "$.name") AS name_string,
JSON_QUERY(json_string, "$.name") IS NULL AS name_string_is_null,
JSON_QUERY(json, "$.name") AS name_json,
JSON_QUERY(json, "$.name") IS NULL AS name_json_is_null
FROM t;
/*-------------+---------------------+-----------+-------------------*
| name_string | name_string_is_null | name_json | name_json_is_null |
+-------------+---------------------+-----------+-------------------+
| NULL | true | null | false |
*-------------+---------------------+-----------+-------------------*/