From: Ragnar <gnari@hive.is>
To: Partha Guha Roy <partha.guha.roy@gmail.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: Need to subtract values between previous and current row
Date: Fri, 15 Dec 2006 13:01:50 +0000
Message-ID: <1166187710.6369.164.camel@localhost.localdomain> (raw)
In-Reply-To: <6bdfe880612150427o19bfe90ch87a972c0f5898ffb@mail.gmail.com>
References: <6bdfe880612150427o19bfe90ch87a972c0f5898ffb@mail.gmail.com>
On fös, 2006-12-15 at 18:27 +0600, Partha Guha Roy wrote:
> Hi,
>
> I have a table that contains data like this:
>
> ID ATIME (MM/dd/yyyy)
> == ====
> 1 10/12/2006
> 2 10/14/2006
> 3 10/18/2006
> 4 10/22/2006
> 5 10/30/2006
>
> Now I need a query that will subtract atime of row 1 from row 2, row2
> from row3 and so on...
if there are no missing IDs you can use a self join
SELECT t1.atime,t2,atime
FROM t AS t1
JOIN t AS t2 ON (t1.ID=t2.ID+1)
otherwise, you could use a loop in a pl/pgpsql function
gnari
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To: pgsql-sql@postgresql.org
Cc: gnari@hive.is, partha.guha.roy@gmail.com
Subject: Re: Need to subtract values between previous and current row
In-Reply-To: <1166187710.6369.164.camel@localhost.localdomain>
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