Re: [SQL] Duplicate rows
От | Andy Lewis |
---|---|
Тема | Re: [SQL] Duplicate rows |
Дата | |
Msg-id | Pine.LNX.3.95.980516090952.15079C-100000@shell.mpsi.net обсуждение исходный текст |
Ответ на | Re: [SQL] Duplicate rows (Oleg Broytmann <phd@comus.ru>) |
Список | pgsql-sql |
Thanks, I'll give it a try. Andy On Sat, 16 May 1998, Oleg Broytmann wrote: >Hi! > >On Sat, 16 May 1998, Andy Lewis wrote: >> Right, I know that there are dups in the column. But, I don't know where they >> are nor do I know their value(s). I want to be able to find, say, two interger >> values that are in the same column but, different rows. > > It seems that you need a correlated subquery - a loop for every row, that >tests whether there are equal values. > >SELECT oid, mycolumn FROM mytable a > WHERE mycolumn IN > (SELECT oid, mycolumn FROM mytable b > WHERE a.oid <> b.oid) > >Or may be, join with the same table. Not sure what is better in this >situation. > >SELECT oid, mycolumn FROM mytable a, mytable b > WHERE a.oid <> b.oid AND > a.mycolumn = b.mycolumn > > In both cases "a.oid <> b.oid" excludes the same row from comparison (I >am pretty sure that in the same row a.mycolumn = b.column :). > >Oleg. >---- > Oleg Broytmann http://members..tripod.com/~phd2/ phd2@earthling.net > Programmers don't die, they just GOSUB without RETURN. > >
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