On Thu, Mar 5, 2009 at 12:29 PM, Steve Atkins <steve@xxxxxxxxxxx> wrote: > > On Mar 5, 2009, at 11:17 AM, Richard Greenwood wrote: > >> Hello pgsql listers, >> >> I've got a problem that is similar to, but I don't think identical to, >> a cross tab query. My data looks like: >> ID | CAT >> 1 | A >> 1 | B >> 2 | A >> 2 | C >> So for each ID there may be many CAT (categories). >> The client wants it to look like: >> ID | CATS >> 1 | A,B >> 2 | A,C >> Where each ID is unique in the results, and the CAT values are >> concatenated with a comma separator. >> >> There are about 100 unique CAT values. They only way I can see to do >> it is programatically with a for loop. But before I do that I wanted >> to bounce it off the fine minds that inhabit this list. > > Sounds like a job for array_accum(), which you can find mentioned > at http://www.postgresql.org/docs/8.3/interactive/xaggr.html > > select id, array_to_string(array_accum(cat), ',') from table group by id; > > There'll be a built-in array_agg() in 8.4, I think. > > Cheers, > Steve Thanks, that looks like what I need! Regards, Rich -- Richard Greenwood richard.greenwood@xxxxxxxxx www.greenwoodmap.com -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
