JSON_OBJECTAGG (Transact-SQL)
Applies to:
Azure SQL Database
Azure SQL Managed Instance
Constructs a JSON object from an aggregation of SQL data or columns.
The key/value pairs can be specified as input values, column, variable references.
To create a JSON array from an aggregate instead, use JSON_ARRAYAGG.
Note
Both json aggregate functions JSON_OBJECTAGG
and JSON_ARRAYAGG
are currently in preview for Azure SQL Database and Azure SQL Managed Instance (configured with the Always-up-to-date update policy).
Transact-SQL syntax conventions
Syntax
JSON_OBJECTAGG ( json_key_value [ json_null_clause ] )
json_key_value ::= <json_name> : <value_expression>
json_null_clause ::= NULL ON NULL | ABSENT ON NULL
Arguments
json_key_value
The key / value pair of the JSON object.
json_null_clause
Optional. Omits the entire property of an object if the value is NULL
, or use JSON null as property value. If omitted, NULL ON NULL
is default.
Examples
Example 1
The following example returns a JSON object with one key and null value.
select JSON_OBJECTAGG ( 'key':null )
Result
{"key":null}
Example 2
The following example constructs a JSON object with three properties from a result set.
SELECT JSON_OBJECTAGG( c1:c2 )
FROM (
VALUES('key1', 'c'), ('key2', 'b'), ('key3','a')
) AS t(c1, c2);
Result
{"key1":"c","key2":"b","key3":"a"}
Example 3
The following example returns a result with two columns. The first column contains the object_id
value. The second column contains a JSON object where the key is the column name and value is the column_id
.
SELECT TOP(5) c.object_id, JSON_OBJECTAGG(c.name:c.column_id) AS columns
FROM sys.columns AS c
GROUP BY c.object_id;
Result
object_id | column_list |
---|---|
3 | {"bitpos":12,"cid":6,"colguid":13,"hbcolid":3,"maxinrowlen":8,"nullbit":11,"offset":10,"ordkey":7,"ordlock":14,"rcmodified":4,"rscolid":2,"rsid":1,"status":9,"ti":5} |
5 | {"cmprlevel":9,"fgidfs":7,"fillfact":10,"idmajor":3,"idminor":4,"lockres":17,"maxint":13,"maxleaf":12,"maxnullbit":11,"minint":15,"minleaf":14,"numpart":5,"ownertype":2,"rcrows":8,"rowsetid":1,"rsguid":16,"scope_id":18,"status":6} |
6 | {"cloneid":6,"dbfragid":8,"id":1,"partid":3,"rowsetid":7,"segid":5,"status":9,"subid":2,"version":4} |
7 | {"auid":1,"fgid":5,"ownerid":3,"pcdata":10,"pcreserved":11,"pcused":9,"pgfirst":6,"pgfirstiam":8,"pgroot":7,"status":4,"type":2} |
8 | {"fileid":2,"filename":4,"name":3,"status":1} |