Re: Delete duplicates
От | Germán Gutiérrez |
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Тема | Re: Delete duplicates |
Дата | |
Msg-id | 000a01c338ec$b9635d00$eaf1fea9@german обсуждение исходный текст |
Ответ на | Delete duplicates ("Rudi Starcevic" <rudi@oasis.net.au>) |
Список | pgsql-sql |
Hi, you need find duplicates and then you remove them delete from aap where id not in ( select max(id) from aap b where aap.keyword = b.keyword ); Germán Sorry about my english -----Mensaje original----- De: pgsql-sql-owner@postgresql.org [mailto:pgsql-sql-owner@postgresql.org] En nombre de Rudi Starcevic Enviado el: Domingo, 22 de Junio de 2003 5:15 Para: pgsql-sql@postgresql.org Asunto: [SQL] Delete duplicates Hi, I have a table with duplicates and trouble with my SQL. I'd like to keep a single record and remove older duplicates. For example below of the 6 recods I'd like to keep records 4 and 6. TABLE: aapid | keyword ----+----------------- 1 | LEAGUE PANTHERS 2 | LEAGUE PANTHERS 3 | LEAGUE PANTHERS 4 | LEAGUE PANTHERS 5 | LEAGUE BRONCOS6 | LEAGUE BRONCOS Here is my SQL so far, it will select records 1 to 5 instead of 1,2,3 and 5 only. Any help greatly appreciated. I think I need a Group By somewhere in there. select a1.id from aap a1 where id < ( SELECT max(id) FROM aap AS a2 ) AND EXISTS ( SELECT * FROM aap AS a2 WHERE a1.keyword = a2.keyword ) Regards Rudi. ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
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