On 03/05/2010, at 9:56 PM, Rainer Döbele wrote:

> Hi Joe,
> 
> There is not a lot, but referring the outer query in an inner query is 
> something you can't do with Empire-db.
> 
> However I would not recommend to use subqueries in the where clause anyway.
> I'd rather solve this with an outer join similar to this:
> 
> select t1.id
> from table1 t1 left join
> ( select t2.id
>  from table2 t2
> ) q1 on q1.id = t1.id
> where q1.id is null
> 
> This is something you can to by wrapping your DBCommand in a DBQuery (see 
> advanced samples for an example).
> 
> Would that be a suitable solution for your problem?
> Regards
> 
> Rainer

Hi Rainer, 

Thanks very much for your suggestion. I hadn't tried that formulation. It is 
approximately the same speed as the one that I posted.

Just out of interest, is there a quick way to explain why subqueries in a where 
clause are to be avoided?

Cheers,
Joe

Reply via email to