JSON_OBJECTAGG
JSON_OBJECTAGG returns a JSON object where the key:value pairs of the object are an aggregate based on rows of a table.
JSON_OBJECTAGG (
[JSON key and value [{,JSON key and value}...]
[NULL|ABSENT ON NULL]
[WITH|WITHOUT UNIQUE [KEYS]]
[RETURNING datatype]
)
where the arguments have the same meaning as described in
JSON_OBJECT.
Example:
SELECT JSON_OBJECTAGG (name VALUE row ABSENT ON NULL) FROM emp;
returns the JSON object {"Frank":1, "Steve":2, "Bob":1}.
SELECT JSON_OBJECTAGG (name VALUE row NULL ON NULL) FROM emp;
generates an error because the last name is NULL, which is invalid.
JSON_OBJECTAGG can be used in GROUP BY clauses.
SELECT emp.row,
JSON_OBJECTAGG (name VALUE emp.unit ABSENT ON NULL) AS units
FROM emp GROUP BY emp.row
returns:
Row units
1 {"Frank":"1A","Bob":"1B"}
2 {"Steve":"2A"}
Last modified date: 11/09/2022