Обсуждение:
i have a table in which duplicate rows occur.
now i have to remove the duplicates. Please note that however, only the duplicate rows have to be deleted and not the original one.
How do i do it?
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Surabhi, search the archives, this has been discussed quite a few times in the pass. regards, - ----- Jonel Rienton http://blogs.road14.com Software Developer, *nix Advocate On Feb 8, 2005, at 11:44 AM, Surabhi Ahuja wrote: > i have a table in which duplicate rows occur. > > now i have to remove the duplicates. Please note that however, only > the duplicate rows have to be deleted and not the original one. > > How do i do it? -----BEGIN PGP SIGNATURE----- Version: PGP 8.1 iQA/AwUBQgjvDeAwOVAnbsGCEQKiwgCgn0JzdJKYXMq3WgeskWTKmg6xCUMAnRz9 +gfpmg4HI+PZPMU+KQcKPuLY =6189 -----END PGP SIGNATURE-----
Please use a relevant subject for your posts. On Tue, Feb 08, 2005 at 23:14:57 +0530, Surabhi Ahuja <surabhi.ahuja@iiitb.ac.in> wrote: > i have a table in which duplicate rows occur. > > now i have to remove the duplicates. Please note that however, only the duplicate rows have to be deleted and not the originalone. > > How do i do it? If the table has oids, then you can delete all but the row with the minimum oid for each set of duplicates. Another option is to do a select distinct into a temp table, a delete and then copy the temp table back. You should also add a constraint so that duplicates can't get back into the table once you have it cleaned up.