| From: | Richard Huxton <dev(at)archonet(dot)com> |
|---|---|
| To: | garry saddington <garry(at)schoolteachers(dot)co(dot)uk> |
| Cc: | pgsql-general(at)postgresql(dot)org |
| Subject: | Re: simplifying SQL |
| Date: | 2007-02-08 08:50:52 |
| Message-ID: | 45CAE46C.7010603@archonet.com |
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| Thread: | |
| Lists: | pgsql-general |
garry saddington wrote:
> I have this query which essentially returns records that exist in one
> table (studentclass) and not another (effortandattainment) to check when
> teachers have entered their student grades.
>
> select
> from studentclass left join effortandattainment
> and studentclass.classid not in (
> I was wondering whether a simpler method exists to do the same thing or
> is this OK.
The formatting on the query isn't great, but I can't quite see what the
"left join" is doing with the "not in" too. I'd probably just have the
left join and check that "effortandattainment.classid IS NULL".
--
Richard Huxton
Archonet Ltd
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