Re: Quick SQL question . . .
От | Marie G. Tuite |
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Тема | Re: Quick SQL question . . . |
Дата | |
Msg-id | IGELKLINGDMODABPOOFECEBNCCAA.marie.tuite@edisonaffiliates.com обсуждение исходный текст |
Ответ на | Quick SQL question . . . ("Peter E. Chen" <pchen3@jhmi.edu>) |
Ответы |
Re: Quick SQL question . . .
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Список | pgsql-general |
Try select identno, count(identno) from some_table group by identno having count(identno) >=1; -----Original Message----- From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org]On Behalf Of Peter E. Chen Sent: Thursday, May 09, 2002 2:39 PM To: pgsql-general@postgresql.org Subject: [GENERAL] Quick SQL question . . . Can anyone tell me what is the easiest way for me to tell if a column is unique or not? I tried using DISTINCT ON and COUNT together in a SELECT statement, but I can't seem to get the query to work: SELECT DISTINCT ON (identno) count(identno) FROM some_table; I was trying to figure out if the # of unique entries for a particular column is equal to the # of total entries for that column. Any suggestions? Peter ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
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