Re: [SQL] Trouble with massive select statement. - Mailing list pgsql-sql

From Darren Greer
Subject Re: [SQL] Trouble with massive select statement.
Date
Msg-id 99062207125208.13060@george
Whole thread Raw
In response to Re: [SQL] Trouble with massive select statement.  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [SQL] Trouble with massive select statement.
List pgsql-sql
See below

> > select distinct username, station 
> >     from testmaster t1 
> >     where 1 < (
> >         select count(t2.username) 
> >             from testmaster t2
> >             where t2.test_date > '05-14-1999' 
> >             and t2.station = 'WZZZ' 
> >             and t1.username = t2.username
> >         )
> > ;
> 
> The above doesn't seem to me to do what you claim you want to do ---
> it seems to be looking for users who have taken the test *more than
> once* in the given interval.
That is correct......my mistake :)

> Assuming that the code is right and the comment wrong ;-), I agree
Good assumption :)

> SELECT username, station FROM testmaster
>   WHERE test_date > '05-14-1999' and station = 'WZZZ' 
>   GROUP BY username, station
>   HAVING count(*) > 1;
This works wonderfully, thanks.  Now comes the other twist.  I already have a
select statement (select first_name, email from listeners l, listeners_data ld
where l.username = ld.username a nd $filter;).  The $filter is a bunch of and
statements that limit the data coming from the table listeners.  I need to get
the select statement you told me to work as a filter on the data that this
select statement grabs.  I cant see an easy way to do this without making this
thing incredibly slow having to chech every user.  Any thoughts?

Darren


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