Re: Flatten table using timestamp and source

On Thursday 24 May 2012, Elrich Marx wrote:
> I am quite new to Postgres, so please bear with me.
>
> I have a table with data in the following format:
>
> Table name : Time_Source_Table
>
> Source , Stime
> 1, "2012-05-24 13:00:00"
> 1, "2012-05-24 13:01:00"
> 1, "2012-05-24 13:02:00"
> 2, "2012-05-24 13:03:00"
> 2, "2012-05-24 13:04:00"
> 1, "2012-05-24 13:05:00"
> 1, "2012-05-24 13:06:00"
>
> I’m trying to get to a result that flattens the results based on
> source, to look like this:
>
> Source, Stime, Etime
> 1, "2012-05-24 13:00:00","2012-05-24 13:02:00"
> 2, "2012-05-24 13:03:00","2012-05-24 13:04:00"
> 1, "2012-05-24 13:05:00","2012-05-24 13:06:00"
>
> Where Etime is the last Stime for the same source.

How do you figure out that the Etime for (1, 13:00:00) is (1, 13:02:00)
and not (1, 13:01:00)?

Regards,

-- Raj
--
Raj Mathur || raju(at)kandalaya(dot)org || GPG:
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