Comments on: How to select the Nth greatest/least/first/last row in SQL http://www.xaprb.com/blog/2008/08/08/how-to-select-the-nth-greatestleastfirstlast-row-in-sql/ Stay curious! Tue, 06 Jan 2009 03:11:13 +0000 http://wordpress.org/?v=2.6.2 By: Xaprb http://www.xaprb.com/blog/2008/08/08/how-to-select-the-nth-greatestleastfirstlast-row-in-sql/#comment-14996 Xaprb Wed, 13 Aug 2008 00:36:16 +0000 http://www.xaprb.com/blog/2008/08/08/how-to-select-the-nth-greatestleastfirstlast-row-in-sql/#comment-14996 Nope, because the first query finds the two cheapest prices for each fruit, so that would effectively be "find the min of the min" which is... the min, or the 1st cheapest. Try it and see! Nope, because the first query finds the two cheapest prices for each fruit, so that would effectively be “find the min of the min” which is… the min, or the 1st cheapest.

Try it and see!

]]> By: Rijk van Wel http://www.xaprb.com/blog/2008/08/08/how-to-select-the-nth-greatestleastfirstlast-row-in-sql/#comment-14995 Rijk van Wel Tue, 12 Aug 2008 20:03:03 +0000 http://www.xaprb.com/blog/2008/08/08/how-to-select-the-nth-greatestleastfirstlast-row-in-sql/#comment-14995 Nice article, but isn't the 2nd cheapest the _least_ expensive of the fruits found in the first query (so "min(price) as second_cheapest")? Nice article, but isn’t the 2nd cheapest the _least_ expensive of the fruits found in the first query (so “min(price) as second_cheapest”)?

]]> By: Jordi Baylina http://www.xaprb.com/blog/2008/08/08/how-to-select-the-nth-greatestleastfirstlast-row-in-sql/#comment-14985 Jordi Baylina Mon, 11 Aug 2008 07:57:01 +0000 http://www.xaprb.com/blog/2008/08/08/how-to-select-the-nth-greatestleastfirstlast-row-in-sql/#comment-14985 A simplification: select sum(price) from fruits f1 where ( select count(*) from fruits f2 where f1.type=f2.type and f2.price <= f1.price ) = 2 If can exists multiple varieties with the same price then: select sum(price) from fruits f1 where ( select count(*) from fruits f2 where f1.type=f2.type and ((f2.price < f1.price) or ( (f2.price=f1.price) and (f2.variety < f1.variety))) ) =1 A simplification:

select sum(price)
from fruits f1
where
( select count(*)
from fruits f2
where f1.type=f2.type and
f2.price <= f1.price
) = 2

If can exists multiple varieties with the same price then:

select sum(price) from fruits f1
where (
select count(*)
from fruits f2
where f1.type=f2.type and
((f2.price < f1.price) or ( (f2.price=f1.price) and
(f2.variety < f1.variety)))

) =1

]]> By: Gints http://www.xaprb.com/blog/2008/08/08/how-to-select-the-nth-greatestleastfirstlast-row-in-sql/#comment-14977 Gints Sat, 09 Aug 2008 21:21:36 +0000 http://www.xaprb.com/blog/2008/08/08/how-to-select-the-nth-greatestleastfirstlast-row-in-sql/#comment-14977 As soon as MySQL will add analytic functions, it will be muuuuch easier :) As soon as MySQL will add analytic functions, it will be muuuuch easier :)

]]> By: Xaprb http://www.xaprb.com/blog/2008/08/08/how-to-select-the-nth-greatestleastfirstlast-row-in-sql/#comment-14972 Xaprb Sat, 09 Aug 2008 02:00:59 +0000 http://www.xaprb.com/blog/2008/08/08/how-to-select-the-nth-greatestleastfirstlast-row-in-sql/#comment-14972 Approach it the other direction. First, get the data on the last post in each thread. See my earlier posts for this. Then join to the threads. Approach it the other direction.

First, get the data on the last post in each thread. See my earlier posts for this.

Then join to the threads.

]]>