Re: Outer join problem

Sorry, Pierre, I don't think I explained myself very well!

The results I want returned are all the descriptions in table B, together with their values from table A (the numerical column), but only if the seqid in A is equal to a given value, otherwise I want a null.

So what you suggest would work in that case because it depends on a seqid being present in both cases (I think!)

Thanks anyway,

/Sarah

Pierre Charpenay wrote:

> Hi,
>
> What you want is :
>
> Some rows of A who have a description (from B)
> AND
> Some rows of A who have no description
>
> That's typically a UNION, so try this :
>
> SELECT a.seqid, b.description, a.numerical_column
> from a, b
> where a.catid=b.catid /* have a description in B */
> and a.seqid='12345'
> UNION
> SELECT a.seqid, 'NO DESC.' description, a.numerical_column
> from a, b
> where a.seqid='12345'
> and not exists (select null from b /* have no description in B */
> where b.catid=a.catid)
> order by 2
>
> --
> Pierre CHARPENAY
Received on Wed Feb 09 2000 - 07:08:06 CST