I want to join a table which has multiple rows and need to merge one of the column from all the rows into single column.
select a.parent_id,a.parent_name,concat(b.child_name) from parent a
join children b on (a.parent_id=b.parent_id);
SELECT a.parent_id, a.parent_name, STRING_AGG(b.child_name, ',') as Children
FROM
Parent a
INNER JOIN children b
ON a.Id = b.ParentId
GROUP BY
a.parent_id
,a.parent_name