Re: (un)grouping question
От | Scott Marlowe |
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Тема | Re: (un)grouping question |
Дата | |
Msg-id | dcc563d10801211145m3ebe4688od195efb1666e52fa@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: (un)grouping question ("Scott Marlowe" <scott.marlowe@gmail.com>) |
Список | pgsql-general |
On Jan 21, 2008 1:45 PM, Scott Marlowe <scott.marlowe@gmail.com> wrote: > On Jan 21, 2008 11:36 AM, Rhys Stewart <rhys.stewart@gmail.com> wrote: > > Hi list, > > > > have the following table > > > > uid|somevalue > > -------------------- > > 1|11 > > 2|44 > > 3|31 > > 4|44 > > 5|71 > > 6|33 > > 7|33 > > 8|44 > > 9|14 > > > > would like to remove the duplicate values in the column somevalue. doing > > this by just adding a random number is perfectly fine, however i want to > > retain at least one of the original values of somevalue. Any ideas how to do > > this in in a query? > > I can get you halfway there. You want a query something like this to > identify all but one of the values: > > select a.uid from sometable a left join sometable b on > (a.somevale=b.somevalue and a.uid > b.uid) > > From there, you'll have to figure out the update part of problem. :) Oh yea, you might need a distinct in that select query.
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