JSON functions in Google Standard SQL

Google Standard SQL supports the following functions, which can retrieve and transform JSON data.

Function overview

JSON extraction functions

The following functions use double quotes to escape invalid JSONPath characters: "a.b".

This behavior is consistent with the ANSI standard.

JSON function Description Return type
JSON_QUERY Extracts a JSON value, such as an array or object, or a JSON scalar value, such as a string, number, or boolean. JSON-formatted STRING or JSON
JSON_VALUE Extracts a scalar value. A scalar value can represent a string, number, or boolean. Removes the outermost quotes and unescapes the values. Returns a SQL NULL if a non-scalar value is selected. STRING
JSON_QUERY_ARRAY Extracts an array of JSON values, such as arrays or objects, and JSON scalar values, such as strings, numbers, and booleans. ARRAY<JSON-formatted STRING> or ARRAY<JSON>
JSON_VALUE_ARRAY Extracts an array of scalar values. A scalar value can represent a string, number, or boolean. 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. ARRAY<STRING>

Other JSON functions

JSON function Description Return type
PARSE_JSON Takes a JSON-formatted string and returns a JSON value. JSON
TO_JSON Takes a SQL value and returns a JSON value. JSON
TO_JSON_STRING Takes a JSON value and returns a JSON-formatted string representation of the value. JSON-formatted STRING

JSON_QUERY

JSON_QUERY(json_string_expr, json_path)

JSON_QUERY(json_expr, json_path)

Description

Extracts a JSON value, such as an array or object, or a JSON scalar value, such as a string, number, or boolean. If a JSON key uses invalid JSONPath characters, then you can escape those characters using double quotes.

  • json_string_expr: A JSON-formatted string. For example:

    '{"class" : {"students" : [{"name" : "Jane"}]}}'

    Extracts a SQL NULL when a JSON-formatted string "null" 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 JSON null 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. If this optional parameter is not provided, then the JSONPath $ symbol is applied, which means that all of the data is analyzed.

    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

If you want to include non-scalar values such as arrays in the extraction, then use JSON_QUERY. If you only want to extract scalar values such strings, numbers, and booleans, then use JSON_VALUE.

Return type

  • json_string_expr: A JSON-formatted STRING
  • 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(json_text, '$') AS json_text_string
FROM UNNEST([
  '{"class" : {"students" : [{"name" : "Jane"}]}}',
  '{"class" : {"students" : []}}',
  '{"class" : {"students" : [{"name" : "John"}, {"name": "Jamie"}]}}'
  ]) AS json_text;

+-----------------------------------------------------------+
| json_text_string                                          |
+-----------------------------------------------------------+
| {"class":{"students":[{"name":"Jane"}]}}                  |
| {"class":{"students":[]}}                                 |
| {"class":{"students":[{"name":"John"},{"name":"Jamie"}]}} |
+-----------------------------------------------------------+

SELECT JSON_QUERY(json_text, '$.class.students[0]') AS first_student
FROM UNNEST([
  '{"class" : {"students" : [{"name" : "Jane"}]}}',
  '{"class" : {"students" : []}}',
  '{"class" : {"students" : [{"name" : "John"}, {"name": "Jamie"}]}}'
  ]) AS json_text;

+-----------------+
| first_student   |
+-----------------+
| {"name":"Jane"} |
| NULL            |
| {"name":"John"} |
+-----------------+

SELECT JSON_QUERY(json_text, '$.class.students[1].name') AS second_student_name
FROM UNNEST([
  '{"class" : {"students" : [{"name" : "Jane"}]}}',
  '{"class" : {"students" : []}}',
  '{"class" : {"students" : [{"name" : "John"}, {"name" : null}]}}',
  '{"class" : {"students" : [{"name" : "John"}, {"name": "Jamie"}]}}'
  ]) AS json_text;

+-------------------+
| second_student    |
+-------------------+
| NULL              |
| NULL              |
| NULL              |
| "Jamie"           |
+-------------------+

SELECT JSON_QUERY(json_text, '$.class."students"') AS student_names
FROM UNNEST([
  '{"class" : {"students" : [{"name" : "Jane"}]}}',
  '{"class" : {"students" : []}}',
  '{"class" : {"students" : [{"name" : "John"}, {"name": "Jamie"}]}}'
  ]) AS json_text;

+------------------------------------+
| student_names                      |
+------------------------------------+
| [{"name":"Jane"}]                  |
| []                                 |
| [{"name":"John"},{"name":"Jamie"}] |
+------------------------------------+

JSON_VALUE

JSON_VALUE(json_string_expr[, json_path])

JSON_VALUE(json_expr[, json_path])

Description

Extracts a scalar value and then returns it as a string. A scalar value can represent a string, number, or boolean. Removes the outermost quotes and unescapes the return values. If a JSON key uses invalid JSONPath characters, then you can escape those characters using double quotes.

  • json_string_expr: A JSON-formatted string. For example:

    '{"class" : {"students" : [{"name" : "Jane"}]}}'

  • json_expr: JSON. For example:

    JSON '{"class" : {"students" : [{"name" : "Jane"}]}}'

  • 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 JSON null or a non-scalar value (in other words, if json_path refers to an object or an array), then a SQL NULL is returned. If this optional parameter is not provided, then the JSONPath $ symbol is applied, which means that the entire JSON-formatted string is analyzed.

If you only want to extract scalar values such strings, numbers, and booleans, then use JSON_VALUE. If you want to include non-scalar values such as arrays in the extraction, then use JSON_QUERY.

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_QUERY_ARRAY

JSON_QUERY_ARRAY(json_string_expr[, json_path])

JSON_QUERY_ARRAY(json_expr[, json_path])

Description

Extracts an array of JSON values, such as arrays or objects, and JSON scalar values, such as strings, numbers, and booleans. If a JSON key uses invalid JSONPath characters, then you can escape those characters using double quotes.

  • json_string_expr: A JSON-formatted string. For example:

    '{"class" : {"students" : [{"name" : "Jane"}]}}'

  • json_expr: JSON. For example:

    JSON '{"class" : {"students" : [{"name" : "Jane"}]}}'

  • 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.

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_VALUE_ARRAY

JSON_VALUE_ARRAY(json_string_expr[, json_path])

JSON_VALUE_ARRAY(json_expr[, json_path])

Description

Extracts an array of scalar values and returns an array of string-formatted scalar values. A scalar value can represent a string, number, or boolean. If a JSON key uses invalid JSONPath characters, you can escape those characters using double quotes.

  • json_string_expr: A JSON-formatted string. For example:

    '{"class" : {"students" : [{"name" : "Jane"}]}}'

  • json_expr: JSON. For example:

    JSON '{"class" : {"students" : [{"name" : "Jane"}]}}'

  • 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.

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 |
+--------+
| []     |
+--------+

-- 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 SQL NULL.
SELECT JSON_VALUE_ARRAY('["world", null, 1]') AS result;

+------------------+
| result           |
+------------------+
| [world, NULL, 1] |
+------------------+

PARSE_JSON

PARSE_JSON(json_string_expr[, wide_number_mode=>{ 'exact' | 'round' } ])

Description

Takes a SQL STRING value and returns a SQL JSON value. The STRING value represents a string-formatted JSON value.

This function supports an optional mandatory-named argument called wide_number_mode that determines how to handle numbers that cannot be stored in a JSON value without the loss of precision. If used, wide_number_mode must include one of these values:

  • exact: 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 wide_number_mode is not used, the function implicitly includes wide_number_mode=>'exact'. 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}   |
+--------------------------------+

TO_JSON

TO_JSON(sql_value[, stringify_wide_numbers=>{ TRUE | FALSE } ])

Description

Takes a SQL value and returns a JSON value. The value must be a supported Google Standard SQL data type. You can review the Google Standard SQL data types that this function supports and their JSON encodings here.

This function supports an optional mandatory-named argument called stringify_wide_numbers.

  • If this argument is TRUE, numeric values outside of the FLOAT64 type domain are encoded as strings.
  • If this argument is not used or is FALSE, numeric values outside of the FLOAT64 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:

  • INT64
  • NUMERIC

If one of these numerical data types appears in a container data type such as an ARRAY or STRUCT, the stringify_wide_numbers argument is applied to the numerical data types in the container data type.

Return type

A JSON value

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

Takes a JSON expression and returns a JSON-formatted string representation of the value from the expression.

Return type

A JSON-formatted STRING

Example

Convert JSON to a JSON-formatted string.

SELECT TO_JSON_STRING(JSON '{"id":1, "coordinates":[10,20]}') AS json_string

+--------------------------------+
| json_string                    |
+--------------------------------+
| {"coordinates":[10,20],"id":1} |
+--------------------------------+

JSON encodings

The following table includes common encodings that are used when a SQL value is encoded as JSON value with the TO_JSON function.

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 stringify_wide_numbers argument is TRUE and the value is outside of the FLOAT64 type domain, the value is encoded as a string. If the value cannot be stored in JSON without loss of precision, the function fails. Otherwise, the value is encoded as a number.

If the stringify_wide_numbers is not used or is FALSE, numeric values outside of the `FLOAT64` 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.

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 stringify_wide_numbers argument is TRUE and the value is outside of the FLOAT64 type domain, it is encoded as a string. Otherwise, it's encoded as a number.

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

+/-inf and NaN are encoded as Infinity, -Infinity, and NaN. Otherwise, this value is encoded as a number.

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, ", \, and the control characters from U+0000 to U+001F are escaped.

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"
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 TO_JSON, a field is included in the output string and any duplicates of this field are omitted.

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, ", \, and the control characters from U+0000 to U+001F are escaped.

SQL input: STRUCT(12 AS purchases, TRUE AS inStock)
JSON output: {"inStock": true,"purchases":12}

JSONPath

Most JSON functions pass in a json_string_expr and json_path parameter. The json_string_expr parameter passes in a JSON-formatted string, and the json_path parameter identifies the value or values you want to obtain from the JSON-formatted string.

The json_string_expr parameter must be a JSON string that is formatted like this:

'{"class" : {"students" : [{"name" : "Jane"}]}}'

You construct the json_path parameter using the JSONPath format. As part of this format, this parameter must start with a $ symbol, which refers to the outermost level of the JSON-formatted string. You can identify child values using dots. If the JSON object is an array, you can use brackets to specify the array index. If the keys contain $, dots, or brackets, refer to each JSON function for how to escape them.

JSONPath Description Example Result using the above json_string_expr
$ Root object or element "$" {"class":{"students":[{"name":"Jane"}]}}
. Child operator "$.class.students" [{"name":"Jane"}]
[] Subscript operator "$.class.students[0]" {"name":"Jane"}

A JSON functions returns NULL if the json_path parameter does not match a value in json_string_expr. 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 is invalid, the function raises an error.