On Mon, 23 Feb 2009 15:44:05 +0000 Richard Huxton <d...@archonet.com> wrote:
> Tarlika Elisabeth Schmitz wrote: > > On Fri, 20 Feb 2009 19:06:48 +0000 > > Richard Huxton <d...@archonet.com> wrote: > >> try something like: > >> > >> SELECT t1.d, t1.s, t1.c, count(*) > >> FROM t1 > >> LEFT JOIN ( > >> SELECT d,s,c FROM t2 WHERE x > >> ) AS t2_true USING (d,s,c) > >> GROUP BY t1.d, t1.s, t1.c; > >> > >> Warning - not tested > > > > Many thanks for the quick reply. > > > > > > This suggestion does not work as it returns a count of 1 even when > > there are no rows in t2 that match (d,s,c) in T1. > > Ah, then rather than count(*) you'll want count(t2_true.d) so when you > get a null because of no match it's not counted. You can use any > column from t2_true. Indeed, that works. Now I am spoilt for choice! -- Best Regards, Tarlika Elisabeth Schmitz A: Because it breaks the logical sequence of discussion Q: Why is top posting bad? -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
