Question

So Postgres is complaining about:

PGError: ERROR:  column "sessions.created_at" must appear in the GROUP BY clause or be used in an aggregate function

But the trouble is, “created_at” does appear in the group by clause:

SELECT     created_at, count(id) as visit_count FROM       "sessions"  WHERE     ("sessions"."site_id" IN (4, 3)) AND ("sessions"."created_at" >= '2011-10-20 00:00:00.000000') AND ("sessions"."created_at" <= '2011-10-27 23:59:59.999999') GROUP BY  date(created_at))

Does it have something to do with created_at being wrapped in date() perhaps?

Thanks in advance!

Answer 1

No, it does not appear.

The GROUP BY contains date(created_at) whereas your SELECT list only contains created_at. If created_at is a timestamp, then these are two different things.

You either need to use GROUPY BY created_at or SELECT date(created_at) (probably the latter)