Date: Fri, 25 Jul 2008 10:22:16 -0500
>> SELECT * FROM parts p1
>> WHERE (SELECT COUNT(DISTINCT p2.unit_cost)
>> FROM parts p2
>> WHERE p2.unit_cost > p1.unit_cost) < 3
> Yes, that's effectively taking the same counting and grouping
> approach, written in a more compact way (although here you just have
> the top 3 and not a range, which would convlute the query
> However, what really jars me in your query though is its implict
> casting of a (nested) relation into an integer as part of the WHERE
Scalar subqueries are considered perfectly respectable amongst SQL enthusiasts, but I confess they do stick in my throat and I have to master myself to stay in character when I am teaching this stuff.
I am a whore. I admit it.
-- RoyReceived on Fri Jul 25 2008 - 17:22:16 CEST