On Mon, 2007-02-19 at 10:58, Salman Tahir wrote: > Hi, > > I have a query regarding an SQL statement I'm trying to execute. I > have the following table: > > sequence > -------------+ > AK > AKCMK > CMKA > > I execute the following statement (Cartesian product): > > SELECT p1.sequence as sequence1, p2.sequence as sequence2 > FROM potential_pairs p1, potential_pairs p2 > > which gives me: > > sequence1 | sequence2 > ----------------+-------------- > AK | AK > AK | AKCMK > AK | CMKA > AKCMK | AK > AKCMK | AKCMK > AKCMK | CMKA > CMKA | AK > CMKA | AKCMK > CMKA | CMKA > (9 rows) > > I want to eliminate duplicates and by duplicate I mean a tuple such as > {AK, CMKA} should be regarded as the same as {CMKA, AK}. So I would > like the following result: > > sequence1 | sequence2 > ----------------+-------------- > AK | AK > AK | AKCMK > AK | CMKA > AKCMK | AKCMK > AKCMK | CMKA > CMKA | CMKA
Oh wait, slightly different thing you meant. OK, you'll want something like: select p1.sequence as sequence1, p2.sequence as sequence2 from potential_pairs p1, potential_pairs p2 where p1.sequence >= p2.sequence ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate