difference between 'exist' and 'in'

[dky1e]

1. What is the difference between 'exist' and 'in' statements?

2. Why don't I get the same results for those querries:
Query1:
select a1.c1 from a a1
where exists
(
select b1.c1 from b b1 where ( a1.c1 = b1.c1 )
)
Query2:
select a1.c1 from a a1
where not exists
(
select b1.c1 from b b1 where ( a1.c1 != b1.c1 )
)

Thanks.

 

[tlbroadbent]

This question has been answered in thread183-265693 of the SQL Server forum.

I recommend joining Tek-Tips so you can get email notification of replies to your posts as well as the ability to list threads in which you participate. I also recommend that you avoid posting in multiple forums unless you don't get an answer in the first forum or are directed to a more appropriate forum. Terry L. Broadbent - DBA
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