Use Exists or just Count?

[jfrost10]

hey guys,

We have a single Save stored proc for many of our business objects. In this proc, we determine whether its an insert or update. We're converting our SP's from having to pass in a bit saying if its inserting or updating, to doing it a bit smarter. We have two options, both that appear to work the same, but I'm curious as to the best one performane and best-practice wise.

Option 1: Exists

If Exists(Select ComboID1, ComboID2, ComboID3 From Table Where ComboID1 = @ID1 And ComboID2 = @ID2 And ComboID3 = @ID3)

begin
Insert...
end

Else

begin
Update...
end

Option 2: Count

Delcare @Counter as int
Select @Counter = Count(ComboID1)From Table Where ComboID1 = @ID1 And ComboID2 = @ID2 And ComboID3 = @ID3)

If @Counter = 0
begin
Insert...
end

Else

begin
Update...
end

Looking forward to your thoughts. Thanks!

D'Arcy

 

[JohnDTampaBay]

IMHO, the EXISTS is more to the point and may perform a little better unless you need the COUNT for anything else.

--John
-----------------------------------
Behold! As a wild ass in the desert
go forth I to do my work.
--Gurnie Hallock (Dune)

 

[vongrunt]

AFAIK in some cases a bit better. Unlike COUNT, EXISTS stops processing after first record was found.

------
"There's a man... He's bald and wears a short-sleeved shirt, and somehow he's very important to me. I think his name is Homer."
(Jack O'Neill, Stargate)