• S_Kumar_S (9/24/2012)

    I logically expect NULL records to be returned here, but they are not. ... Is there some setting which impacts this behavior?

    Yes there is a setting, but you should be extremely cautious about using it:

    SET ANSI_NULLS OFF

    create table a(id int, nm varchar(200))

    insert into a

    select 1,'a'

    insert into a

    select 1,NULL

    select * from a where nm not in('a')

    SQL DBA,SQL Server MVP(07, 08, 09) "It's a dog-eat-dog world, and I'm wearing Milk-Bone underwear." "Norm", on "Cheers". Also from "Cheers", from "Carla": "You need to know 3 things about Tortelli men: Tortelli men draw women like flies; Tortelli men treat women like flies; Tortelli men's brains are in their flies".