JSON support

[xiongjiwei]

The JSON type is supported in tidb but not GA yet. This issue will trace the JSON GA project.

Goal

make the basic function is available

Non-Goal

multi-valued index
Partial update

Issue track

• json format
  • Support JSON object with key length >= 65536 #21781
  • json opaque value has different behavior with MySQL after stored #37443
• json-path-syntax compatibility
  • Json function is not compatible with Mysql #22525
  • JSON_REPLACE/JSON_REMOVE etc does not return error for invalid path expressions #34959
• type convert
  • json cast for enum is not same with MySQL #9999
  • Convert from json opaque value to other types are not supported #37342
  • Support convert to other type from json opaque value #37387
  • conversion from enum to JSON is not compatible with MySQL #25329
  • JSON data type does not support custom types (i.e. MySQL types) #9988
  • implicit cast rule of json scalar is different with MySQL #37504 (implicit convert)
  • create json value from string with binary charset should report error #37509
  • In the test cases in TiDB, MySQL and TiDB behave differently, whichever prevails #31104
  • JSON field should only accept JSON text #10469
  • Remove unnecessary decimal when serialize json float tikv/tikv#13451
  • json float format should have extra .0 if it's an integer #37806
• comparison
  • Cast other types to JSON when compared with JSON value #37403
  • The comparison between json and binary is different from MySQL  #31918
  • can't use collate clause for json when the new collation is enabled #31640
  • json comparison is not compatible with MySQL after push down #37481
  • order by of json value is different with MySQL #37506
• json function correctness
  • json_objectagg() is not compatible with MySQL on varbinary type #25053
  • Support automatic conversion from binary/time in the json_(object|array) function tikv/tikv#13341
  • some json functions' return type is not compatible with mysql #37339
  • json_unquote && json_extract with asterisk push down tikv bug #37450
  • JSON_ARRAYAGG reprot unsupported second argument type #37287
  • JSON_QUOTE() in derived table is not working in Tidb: #30132
  • extra double quotes for result of json_search #25579
  • executor: select agg from json column return wrong result with the MySQL #25033
  • json_quote return different result #37294
  • JSON document does not report error even exceeds the maximum depth. #37292
  • A minor compatible issue when binary string is used for json_unquote #25580
• tikv json function
  • json_unquote and like operator has different behavior after pushing down to TiKV #37501
• generate columns and expression index with json functions
  • expression index is not applied when using json_unquote(json_extract(xxx)) #37478
  • Generated columns index replacement rule not support JSON functions like MySQL #35490

[xiongjiwei]

close due to json is GA