Re: 7.4 Wishlist
От | Magnus Naeslund(f) |
---|---|
Тема | Re: 7.4 Wishlist |
Дата | |
Msg-id | 06d201c29a51$4d98c040$f80c0a0a@mnd обсуждение исходный текст |
Ответ на | Re: 7.4 Wishlist (Stephan Szabo <sszabo@megazone23.bigpanda.com>) |
Ответы |
Re: 7.4 Wishlist
Re: 7.4 Wishlist |
Список | pgsql-hackers |
Stephan Szabo <sszabo@megazone23.bigpanda.com> 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. Magnus
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