From: John Lister <john.lister-ps@kickstone.com>
To: pgsql-sql@postgresql.org
Subject: obtaining difference between minimum value and next in size
Date: Wed, 17 Nov 2010 15:11:32 -0000
Message-ID: <3BC753A3784F488F98304300B6E437FD@squarepi.com> (raw)
Hi, I was wondering if it is possible to do this with a single query rather than iterate over all of the rows in an application:
I have a table which for brevity looks like:
create table offers {
integer id;
integer product_id;
double price;
}
where for each product there is a number of offers in this table. Now my question:
Is it possible to obtain the difference between just the minimum price and the next one up per product, so say I have the following data:
id, product_id, price
123, 2, 10.01
125, 2, 10.05
128, 2, 11.30
134, 3, 9.45
147, 3, 11.42
157, 3, 12.08
167, 3, 12.09
then I would like the following returned
product_id, difference
2, .04 (10.05-10.01)
3, 1.97 (11.42-9.45)
,etc
Any ideas?
Thanks
John
--
Got needs? Get Goblin'! - http://www.pricegoblin.co.uk/
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To: pgsql-sql@postgresql.org
Cc: john.lister-ps@kickstone.com
Subject: Re: obtaining difference between minimum value and next in size
In-Reply-To: <3BC753A3784F488F98304300B6E437FD@squarepi.com>
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