Re: Selecting latest value II

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От Haller Christoph
Тема Re: Selecting latest value II
Дата
Msg-id 200109201402.QAA25852@rodos
обсуждение исходный текст
Ответ на Re: Selecting latest value  (Patrik Kudo <kudo@partitur.se>)
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What do you mean by 
"the latest val for each userid" 
I cannot understand how a value of type integer 
can have a attribute like "latest". 
Sorry, but I need at least a bit more information. 
Regards, Christoph 
> 
> On Thu, 20 Sep 2001, Haller Christoph wrote:
> 
> > Try
> > create NEWtable (userid text, val integer, ts timestamp);
> > insert into NEWtable
> > select userid, val, max(ts) from table group by userid, val;
> 
> That won't work. That will give me multiple userid-val combinations. Sure,
> the userid-val combinations will be unique, but I want unique userids
> with only the latest val for each userid.
> 
> /Patrik Kudo
> 
> > >
> > > Hi,
> > >
> > > I have a table which basically looks like this:
> > >
> > > create table (userid text, val integer, ts timestamp);
> > >
> > > This table holds multiple values for users, timestamped for history
> > > reasons.
> > >
> > > Now I need to fetch the latest val for each userid to insert into a new
> > > table (with about the same schema, except for uniqueness on userid).
> > > I belive this should be a trivial task, but I'm experience total lack of
> > > insight here...
> > >
> > > Comments?
> > >
> > > /Patrik Kudo
> > >
> >
> 
> 



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