David and Seth Thanks. That helped.
When I have select distinct on (revf3) f1, f2, f3, revers(f3) as revf3 from table order by revf3 Is there a way to return just f1, f2, f3 in my results and forget revf3 (so it doesn't show in results)? Thanks. On Fri, Dec 21, 2012 at 9:57 AM, Seth Gordon <se...@ropine.com> wrote: > If you only want one value per id, then your query should be “SELECT > DISTINCT ON (id) ...” > > If you care about which particular value is returned for each ID, then you > have to sort the results: e.g., if you want the minimum value per id, your > query should be “SELECT DISTINCT ON (id) ... ORDER BY value”. The database > will sort the query results before running them through the DISTINCT filter. > > > On Fri, Dec 21, 2012 at 11:31 AM, Wes James <compte...@gmail.com> wrote: > >> If a query returns, say the following results: >> >> id value >> 0 a >> 0 b >> 0 c >> 1 a >> 1 b >> >> >> >> How do I just choose a preferred element say value 'a' over any other >> elements returned, that is the value returned is from a subquery to a >> larger query? >> >> Thanks. >> > >
