Hi,
From MySQL 5.7, It supports SQL standard 99 and implements the feature
such functional dependent on the GROUP By columns, i.e., it detects the
non-aggregate columns which are functionally dependent on the GROUP BY columns
(not included in GROUP BY) and then executes the query without error.
For example,
SELECT a.sno,b.sno,a.name,b.location FROM Name AS a JOIN Location AS b ON
a.sno=b.sno GROUP BY a.sno,b.location
In this case, a.sno is a primary key so no need to include a.name in GROUP By
as it would be identified by the primary key and then for b.sno which is again
equated with a.sno (primary key) so no need to add this as well but for
b.location, we need to add it in GROUP BY or we should use any aggregate
function over this column to avoid error. For more info, please check on the
below link https://dev.mysql.com/doc/refman/5.7/en/group-by-handling.html
Is there any plans on supporting this in Postgres in future versions ?
Thank You,
Arun Kumar
