On Mon, 2 Dec 2002, Magnus Naeslund(f) wrote: > Stephan Szabo <[EMAIL PROTECTED]> wrote: > > > > If you use a scalar subquery, yes, but I think a subselect in from > > would help, maybe something like (if you want the total count) > > > > select table_name.id, sum(sum_col)||'/'||t2.count from table_name, > > (select count(*) as count from table_name) as t2 group by > > table_name.id,t2.count; > > > > or (if you want each count the counter per group) either > > > > select id, sum(sum_col)||'/'||count(*) from table_name > > group by id; > > > > or > > > > select table_name.id, sum(sum_col)||'/'||t2.count from table_name, > > (select id, count(*) as count from table_name group by id) as t2 where > > table_name.id=t2.id group by table_name.id,t2.count; > > > > Give it up already, i was MAKING A POINT, not trying to make an > optimized count(*) thing :) > There are other examples that you cannot get around, that will be > evaluated more than once when a local "user variable" would make it not > need to.
For most cases sticking an expression in a subselect in from works to not re-evaluate it (unless it's correlated in which case I don't think local variables help). It might not be as optimal in all cases, but probably is sufficient in most cases. ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
