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JSON_DEPTH(json_doc)

Returns the maximum depth of a JSON document. ReturnsNULL if the argument isNULL. An error occurs if the argument is not a valid JSON document.

An empty array, empty object, or scalar value has depth 1. A nonempty array containing only elements of depth 1 or nonempty object containing only member values of depth 1 has depth 2. Otherwise, a JSON document has depth greater than 2.

mysql> SELECT JSON_DEPTH('{}'), JSON_DEPTH('[]'), JSON_DEPTH('true');+------------------+------------------+--------------------+| JSON_DEPTH('{}') | JSON_DEPTH('[]') | JSON_DEPTH('true') |+------------------+------------------+--------------------+|                1 |                1 |                  1 |+------------------+------------------+--------------------+mysql> SELECT JSON_DEPTH('[10, 20]'), JSON_DEPTH('[[], {}]');+------------------------+------------------------+| JSON_DEPTH('[10, 20]') | JSON_DEPTH('[[], {}]') |+------------------------+------------------------+|                      2 |                      2 |+------------------------+------------------------+mysql> SELECT JSON_DEPTH('[10, {"a": 20}]');+-------------------------------+| JSON_DEPTH('[10, {"a": 20}]') |+-------------------------------+|                             3 |+-------------------------------+

JSON_LENGTH(json_doc[,path])

Returns the length of a JSON document, or, if apath argument is given, the length of the value within the document identified by the path. ReturnsNULL if any argument isNULL or thepath argument does not identify a value in the document. An error occurs if thejson_doc argument is not a valid JSON document or thepath argument is not a valid path expression.

The length of a document is determined as follows:

mysql> SELECT JSON_LENGTH('[1, 2, {"a": 3}]');+---------------------------------+| JSON_LENGTH('[1, 2, {"a": 3}]') |+---------------------------------+|                               3 |+---------------------------------+mysql> SELECT JSON_LENGTH('{"a": 1, "b": {"c": 30}}');+-----------------------------------------+| JSON_LENGTH('{"a": 1, "b": {"c": 30}}') |+-----------------------------------------+|                                       2 |+-----------------------------------------+mysql> SELECT JSON_LENGTH('{"a": 1, "b": {"c": 30}}', '$.b');+------------------------------------------------+| JSON_LENGTH('{"a": 1, "b": {"c": 30}}', '$.b') |+------------------------------------------------+|                                              1 |+------------------------------------------------+

JSON_TYPE(json_val)

Returns autf8mb4 string indicating the type of a JSON value. This can be an object, an array, or a scalar type, as shown here:

mysql> SET @j = '{"a": [10, true]}';mysql> SELECT JSON_TYPE(@j);+---------------+| JSON_TYPE(@j) |+---------------+| OBJECT        |+---------------+mysql> SELECT JSON_TYPE(JSON_EXTRACT(@j, '$.a'));+------------------------------------+| JSON_TYPE(JSON_EXTRACT(@j, '$.a')) |+------------------------------------+| ARRAY                              |+------------------------------------+mysql> SELECT JSON_TYPE(JSON_EXTRACT(@j, '$.a[0]'));+---------------------------------------+| JSON_TYPE(JSON_EXTRACT(@j, '$.a[0]')) |+---------------------------------------+| INTEGER                               |+---------------------------------------+mysql> SELECT JSON_TYPE(JSON_EXTRACT(@j, '$.a[1]'));+---------------------------------------+| JSON_TYPE(JSON_EXTRACT(@j, '$.a[1]')) |+---------------------------------------+| BOOLEAN                               |+---------------------------------------+

JSON_TYPE() returnsNULL if the argument isNULL:

mysql> SELECT JSON_TYPE(NULL);+-----------------+| JSON_TYPE(NULL) |+-----------------+| NULL            |+-----------------+

An error occurs if the argument is not a valid JSON value:

mysql> SELECT JSON_TYPE(1);ERROR 3146 (22032): Invalid data type for JSON data in argument 1to function json_type; a JSON string or JSON type is required.

For a non-NULL, non-error result, the following list describes the possibleJSON_TYPE() return values:

JSON_VALID(val)

Returns 0 or 1 to indicate whether a value is valid JSON. ReturnsNULL if the argument isNULL.

mysql> SELECT JSON_VALID('{"a": 1}');+------------------------+| JSON_VALID('{"a": 1}') |+------------------------+|                      1 |+------------------------+mysql> SELECT JSON_VALID('hello'), JSON_VALID('"hello"');+---------------------+-----------------------+| JSON_VALID('hello') | JSON_VALID('"hello"') |+---------------------+-----------------------+|                   0 |                     1 |+---------------------+-----------------------+