When grilled further on (Mon, 12 Jan 2004 07:28:09 +0100),
Tomasz Myrta <jasiek@klaster.net> confessed:
> Dnia 2004-01-12 05:04, U¿ytkownik Robert Creager napisa³:
> >
> > SELECT date_trunc( 'hour', "when" )::timestamp AS
> > period FROM readings WHERE period NOT IN (SELECT "time" FROM
> > hour.summary_period) GROUP BY period ORDER BY period;
> >
> > The error is:
> >
> > ERROR: column "period" does not exist
> >
> Your problem has nothing to "NOT IN".
> Your query works fine, when you remove column alias from WHERE clause -
> it's beacause WHERE clause is executed *before* data output (and before
> column aliases). You can still use column aliases in "GROUP BY" and
> "ORDER BY".
Thanks for the info.
So now I have:
SELECT p.period FROM (SELECT date_trunc( 'hour', "when" )::timestamp AS period
FROM readings GROUP BY period) AS p WHERE p.period NOT IN (SELECT "time" FROM
hour.summary_period) ORDER BY p.period;
which appears works as expected. Anything obviously goofy with the above query?
Cheers,
Rob
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