RE: Find non-unique "key" values via SQL

The reason for this is that the where conditions are applied before
aggregation and the having clause is applied after aggregation, so if
you wanted to use a sum() function and then drop all of the rows that
did not have a certain sum, you would have to use a having clause. I
assume that it has to come after the group by because it needs to count
up the rows before it can check the having clause, and it needs the
group by to know how to count up the rows.

Chris

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Dan
Sent: Tuesday, January 09, 2007 3:15 PM
To: Midrange Systems Technical Discussion
Subject: Re: Find non-unique "key" values via SQL

On 1/9/07, Alan Shore <AlanShore@xxxxxxxx> wrote:

select daCusN, count(*) from OPLOGDATA
    HAVING count(*) > 1
    group by daCusN

Boy, SQL's finicky with English usage, ain't it?  ;-)

Thanks for the tip, Alan.  Not sure why, but I had to switch the HAVING
line
with the GROUP BY line to get it to work:

    select daCusN, count(*) from OPLOGDATA
        group by daCusN
        HAVING count(*) > 1

Thanks,
Dan