On Thu, 9 Mar 2006, Tony Smith wrote: > I have two tables action and group: > > action > ------------------------ > id, > name > > group: > ------------------------ > action_id > rank > > I what to select from action table by order by the > rank in the group table. > > If I use > > select * from action where id in (select action_id > from group order by rank) > > The action may not be ordered by rank. How can I do > it?
Well, I think any answer is going to depend on a few pieces of information about the layout and desired behavior. Is group.action_id unique? If so, probably converting it into a join is easiest, I think that'd be something like: select action.* from action, group where action.id=group.action_id order by rank If not, which rank do you want to use from group for a matching id? You could probably then do something with group by and an aggregate. ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq