From: Elrich Marx <elrich.marx@rorotika.com>
To: raju@linux-delhi.org
To: pgsql-sql@postgresql.org
Subject: Re: Flatten table using timestamp and source
Date: Thu, 24 May 2012 14:10:28 +0200
Message-ID: <43a608eb27c08adad0ae99c3409eb1fd@mail.gmail.com> (raw)
In-Reply-To: <201205241729.21270.raju@linux-delhi.org>
References: <73a6b75b83b37093e5e2751fc59c4323@mail.gmail.com>
<201205241729.21270.raju@linux-delhi.org>
HI Raj
If source changes, in this case from 1 to 2, then etime would be the last
value of stime for source =1; So for source 1 it starts at stime 13:00 and
continues till 13:02 (etime).
This should result in 3 records, because source is 1, then 2, then 1 again.
I hope this explains ?
-----Original Message-----
From: pgsql-sql-owner@postgresql.org [mailto:pgsql-sql-owner@postgresql.org]
On Behalf Of Raj Mathur (??? ?????)
Sent: 24 May 2012 01:59 PM
To: pgsql-sql@postgresql.org
Subject: Re: [SQL] 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@kandalaya.org || GPG:
http://otheronepercent.blogspot.com || http://kandalaya.org || CC68
It is the mind that moves || http://schizoid.in || D17F
--
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Subject: Re: Flatten table using timestamp and source
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