Jure Ložar <[EMAIL PROTECTED]> schrieb: > Hi. > > Is it possible to limit number of left join rows that match condition to 1? > I don't want to have hits from first table multiplied when more then 1 row > matches on left join condition.
I'm not sure if i understand you correctly, but perhaps this is what you are searching for: Suppose, you have 2 tables, master and detail: test=# select * from master; id ---- 1 2 (2 rows) test=# select * from detail; id | val ----+----- 1 | 200 2 | 200 1 | 100 (3 rows) This is the left join: test=# select m.id, d.val from master m left join detail d on m.id=d.id; id | val ----+----- 1 | 100 1 | 200 2 | 200 (3 rows) But you need only one row from detail, which? Suppose, this one with the max(val) value: test=# select m.id, d.val from master m left join (select id, max(val) as val from detail group by id) d on m.id=d.id; id | val ----+----- 1 | 200 2 | 200 (2 rows) Is this okay for you? Andreas -- Really, I'm not out to destroy Microsoft. That will just be a completely unintentional side effect. (Linus Torvalds) "If I was god, I would recompile penguin with --enable-fly." (unknow) Kaufbach, Saxony, Germany, Europe. N 51.05082°, E 13.56889° ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
