> -----Original Message-----
> From: Dan Nelson [mailto:dnelson@stripped]
> Sent: Tuesday, September 17, 2002 12:31 PM
> To: Brian Reichert
> Cc: Richard Unger; mysql@stripped
> Subject: Re: aggregate functions producing bad data
>
>
> In the last episode (Sep 17), Brian Reichert said:
> > On Tue, Sep 17, 2002 at 11:59:42AM -0700, Richard Unger wrote:
> > > My query:
> > >
> > > SELECT
> > > count(id),
> > > count( IF(call_end - call_start > 5, id, NULL) ),
> > > count( IF(call_end - call_start <= 5, id, NULL) )
> > > FROM
> > > t_calllog_calls;
> > >
> > > My result:
> > >
> > > 1994
> > > 1956
> > > 35
> > >
> > > However, 1956 + 35 != 1994.
> > >
> > > Running MySQL 3.23.49-nt
> >
> > One thing I'd check: what happens if t_calllog_calls.id is NULL?
>
> Also check if call_end or call_start are NULL; that will
> cause both IFs
> to fail. Don't you love NULLs :)
>
Ooh, good suggestion. I hadn't thought of that!
...but no, none of the call_start or call_end fields are NULL.
Yeah, I love nulls :)
Cheers,
Rich
