Check empty Guid in SQL

Question

Hello everyone!

How do I check is argument in SP Empty Guid or not?

Thanks.

Answer 1

SELECT CAST(CAST(0 AS BINARY) AS UNIQUEIDENTIFIER)

That should return your empty guid.

So to check for that, you would do

IF @GuidParam = CAST(CAST(0 AS BINARY) AS UNIQUEIDENTIFIER)
BEGIN
   --Giud is empty
END

Answer 2

Since the empty guid never changes, the other obvious way is to simply use 00000000-0000-0000-0000-000000000000 rather than calculating it.

If @Param = '00000000-0000-0000-0000-000000000000'
...

Or, if in an procedure, you can set a parameter to act as a constant:

Declare @EmptyGuid uniqueidentifier
Set @EmptyGuid = '00000000-0000-0000-0000-000000000000'

Or you could create a scalar user-defined function which simply returns the above constant value (or recalculates it as in Meiscooldude solution).