Function jsonTypeOf

Get the JSON value's type (object/array/string/number/boolean/null/...).

• mysql/mariadb: JSON_TYPE(col) -> native.
• postgres/cockroachdb: jsonb_typeof(col) -> native.
• sqlite: json_type(col) -> native.
• snowflake: TYPEOF(col) -> native (works on VARIANT).
• clickhouse: JSONType(col) -> native.
• mssql, oracle, redshift, db2: throw "not supported" - none of these expose a documented function that returns the JSON value's type as a string (SQL Server's ISJSON(col, 'object'|'array') only returns a boolean for two of the possible types, not a general type name).