Re: [HACKERS] Table aliases in delete statements?
От | Bruce Momjian |
---|---|
Тема | Re: [HACKERS] Table aliases in delete statements? |
Дата | |
Msg-id | 199912080105.UAA18591@candle.pha.pa.us обсуждение исходный текст |
Ответ на | Re: [HACKERS] Table aliases in delete statements? (Keith Parks <emkxp01@mtcc.demon.co.uk>) |
Список | pgsql-hackers |
> >Don't use s1. Just refer to native deltest in the subquery. That > >should reference the outer table. > > That doesn't seem to work as 3 rows are deleted and not just the > two duplicates. > > emkxp01=> delete from deltest where respdate not in ( select min(s2.respdate) > from deltest s2 where sessionid = s2.sessionid); > DELETE 3 > emkxp01=> select * from deltest; > sessionid | respdate > -----------+------------------------------ > 1 | Tue 07 Dec 22:32:01 1999 GMT > (1 row) No. Use: emkxp01=> delete from deltest where respdate not in ( select min(s2.respdate) from deltest s2 where deltest.sessionid = s2.sessionid); ^^^^^^^ -- Bruce Momjian | http://www.op.net/~candle maillist@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026
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