Re: [personal] Re: Filtering duplicated row with a trigger
От | Nabil Sayegh |
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Тема | Re: [personal] Re: Filtering duplicated row with a trigger |
Дата | |
Msg-id | 3F81A3ED.8000705@e-trolley.de обсуждение исходный текст |
Ответ на | Re: [personal] Re: Filtering duplicated row with a trigger (papapep <papapep@gmx.net>) |
Список | pgsql-novice |
papapep wrote: > If so, how should I do > the duplicates control in the temp table? (for me is as difficult as my > first question :-( ) > Consider that the primary key that we use to see if the row is > duplicated, or not, is a 5 fields key (it has to be so, is a complex > data to filter). CREATE TEMP TABLE tempo (a int, b int, c text); INSERT INTO tempo (a,b,c) values (1,1,'foo'); INSERT INTO tempo (a,b,c) values (1,2,'bar'); INSERT INTO tempo (a,b,c) values (1,1,'foo'); INSERT INTO tempo (a,b,c) values (1,1,'foo'); INSERT INTO tempo (a,b,c) values (1,1,'foo-bar'); SELECT distinct on (a,b) a, b, c from tempo; a | b | c ---+---+----- 1 | 1 | foo 1 | 2 | bar (2 Zeilen) This DISTINCT ON select only cares for the given arguments (a,b) to be distinct. Which c is returned is undefined (random). HTH -- e-Trolley Sayegh & John, Nabil Sayegh Tel.: 0700 etrolley /// 0700 38765539 Fax.: +49 69 8299381-8 PGP : http://www.e-trolley.de
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