I did try the following: SELECT DISTINCT ON (two.two_id) two.two_value FROM one,two WHERE (one.two_id=two.two_id AND one.updatenr > two.updatenr) ORDER BY two.updatenr ASC;
I thought this would a) order the result list by updatenr b) return the first record only for records that are equal on the two.two_id field which would return exactly what I need - return the record with the But what I get instead is "ERROR: SELECT DISTINCT ON expressions must match initial ORDER BY expressions" *grrrmpfh* But after a while playing around I noticed that the "initial" in that sentence above is important - adding two.two_id as first argument to the ORDER BY does not change the result but fulfill the requirements - the expressions don't have to be excactly the same - just the initial argument. My view which returns the (hopefully) correct results: SELECT DISTINCT ON (two.two_id) two.two_value FROM one, two WHERE ((one.two_id = two.two_id) AND (one.updatenr > two.updatenr)) ORDER BY two.two_id, two.updatenr; Next step is to include corresponding information from table three - now I need subselects right? no way around with this DISTINCT and ORDER by stuff in it ... Many thanks for your help so far, Oliver Quoting Oliver Heinz <[EMAIL PROTECTED]>: > I'll try this tomorrow - combining DISTINCT ON (two.two_id) and sorting by > two.updatenr could (should) have the desired effect - I never thought about > using ORDER and DISTINCT that way. > > I'll report my success or failure... > > Thanks so far! > > Bye, > Oliver ------------------------------------------------- This mail sent through IMP: http://horde.org/imp/ ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
