[Zope-DB] SQL-subselect question

Charlie Clark charlie@begeistert.org
Thu, 21 Nov 2002 10:54:52 +0100


On 2002-11-21 at 10:04:55 [+0100], Smith, Neil (Worcester) wrote:
> If I've got it right about what you want (and I'm not sure I have), what 
> about
> 
> SELECT * 
> FROM  
>    mytable mytable1, 
>    mytable mytable2, 
>    anothertable
> WHERE
>    anothertable.value = 'something' AND
>    mytable1.f_key = anothertable.f_key AND
>    mytable2.f_key = anothertable.f_key AND
>    mytable1.ext_id1 = 1 AND
>    mytable2.ext_id2 = 1
> 
> If it performs poorly, you might need some indexes.  Indexing f_key on 
> both tables would be a start, after that it depends very much on what the 
> data is like as to what is best to index.  

Yes, I think that should work. It seems a bit strange to have to rename the 
same table over and over again to do it though which does suggest I should 
use separate tables in the first place.

Thanx

Charlie