MySQL 8.0 Reference Manual Including MySQL NDB Cluster 8.0

12.17.1 JSON Function Reference

Table 12.21 JSON Functions

Name Description
JSON_ARRAY() Create JSON array
JSON_ARRAY_APPEND() Append data to JSON document
JSON_ARRAY_INSERT() Insert into JSON array
-> Return value from JSON column after evaluating path; equivalent to JSON_EXTRACT().
JSON_CONTAINS() Whether JSON document contains specific object at path
JSON_CONTAINS_PATH() Whether JSON document contains any data at path
JSON_DEPTH() Maximum depth of JSON document
JSON_EXTRACT() Return data from JSON document
->> Return value from JSON column after evaluating path and unquoting the result; equivalent to JSON_UNQUOTE(JSON_EXTRACT()).
JSON_INSERT() Insert data into JSON document
JSON_KEYS() Array of keys from JSON document
JSON_LENGTH() Number of elements in JSON document
JSON_MERGE() (deprecated 8.0.3) Merge JSON documents, preserving duplicate keys. Deprecated synonym for JSON_MERGE_PRESERVE()
JSON_MERGE_PATCH() Merge JSON documents, replacing values of duplicate keys
JSON_MERGE_PRESERVE() Merge JSON documents, preserving duplicate keys
JSON_OBJECT() Create JSON object
JSON_PRETTY() Print a JSON document in human-readable format
JSON_QUOTE() Quote JSON document
JSON_REMOVE() Remove data from JSON document
JSON_REPLACE() Replace values in JSON document
JSON_SEARCH() Path to value within JSON document
JSON_SET() Insert data into JSON document
JSON_STORAGE_FREE() Freed space within binary representation of a JSON column value following a partial update
JSON_STORAGE_SIZE() Space used for storage of binary representation of a JSON document
JSON_TABLE() Return data from a JSON expression as a relational table
JSON_TYPE() Type of JSON value
JSON_UNQUOTE() Unquote JSON value
JSON_VALID() Whether JSON value is valid

MySQL supports two aggregate JSON functions JSON_ARRAYAGG() and JSON_OBJECTAGG(). See Section 12.20, “Aggregate (GROUP BY) Functions”, for descriptions of these.

MySQL also supports pretty-printing of JSON values in an easy-to-read format, using the JSON_PRETTY() function. You can see how much storage space a given JSON value takes up, and how much space remains for additional storage, using JSON_STORAGE_SIZE() and JSON_STORAGE_FREE(), respectively. For complete descriptions of these functions, see Section 12.17.7, “JSON Utility Functions”.