Why doesn't “WHERE column = NULL” throw an error in SQL Server? [duplicate]

Answer 1

That is because a NULL can't be equated to any value.

Disable the ANSI_NULLS option and then run it you will see the row now:

SET ANSI_NULLS OFF
select * from #foo --returns the one record we just created  
select * from #foo where colA = null --does not throw an error and does not return a record! why?? 
select * from #foo where colA is null --returns the record  drop table #foo