> Thanks bruce and hermit for all the comments,
> I looked into the book "The SQL Standard" fourth edition of Date
> and in the appendixes page 439 they have an example which they
> discuss. The example is: select count(*) as x from mt having 0 = 0;
> with an empty table they say logically correct it should return one
> column and no rows but sql gives a table of one column and one
> row. So I think it's true that HAVING has to have an aggregation
> but it will also be possible use a non-aggregation.
>
> If I look in our crash-me output page (this is a handy thing for this
> kind of questions) and look for all the other db's to see what they
> do I can say the following thing:
> Informix,Access,Adabas,db2,empress,ms-sql,oracle,solid and
> sybase are all supporting non-aggregation in having clause.
> At this moment everyone except postgres is supporting it.
>
> The change which I can made is to remove the if structure around
> the having tests so that having with group functions will also be
> tested in the crash-me test.
>
> I will try the patch of bruce for the comment part. It shouldn't be the
> way that the perl module is stripping the comments of the querie
> but it is possible and if it is possible it will be a bug in the DBD
> postgresql perl module.
Maybe we should support the HAVING without aggregates. What do others
think?
-- Bruce Momjian | http://www.op.net/~candle maillist@candle.pha.pa.us | (610)
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