set ansi_defaults on
go
create table #main_tbl(i int)
create table #in_tbl(i int)

insert #main_tbl values(1)
insert #main_tbl values(NULL)

insert #in_tbl values(2)
insert #in_tbl values(NULL)

select *from #in_tbl
select *from #main_tbl

go
Print 'Results with NULL in the main table & in_tbl...'
Print ''
select * from #main_tbl m where m.i not in(select i.i from #in_tbl i)

select * from #main_tbl m where not exists(select i.i from #in_tbl i where i.i = m.i )

select m.i from #main_tbl m left join #in_tbl i 
on i.i = m.i 
where i.i is null
go
Print 'Results with NULL in the in_tbl only...'
Print ''
update #main_tbl set i = 2 where i is null

select * from #main_tbl m where m.i not in(select i.i from #in_tbl i)

select * from #main_tbl m where not exists(select i.i from #in_tbl i where i.i = m.i )

select m.i from #main_tbl m left join #in_tbl i 
on i.i = m.i 
where i.i is null
go
Print 'Results with NULL in the main table only...'
Print ''
update #main_tbl set i = null where i  = 2
update #in_tbl set i = 3 where i is null

select * from #main_tbl m where m.i not in(select i.i from #in_tbl i)

select * from #main_tbl m where not exists(select i.i from #in_tbl i where i.i = m.i )

select m.i from #main_tbl m left join #in_tbl i 
on i.i = m.i 
where i.i is null
go

This page was last updated on May 01, 2006 04:28 PM.