Does the order of operation that you place your
RTRIM matter when used in conjunction with
ISNULL? For instance, take the following example where a user potentially enters a bunch of spaces in a field, but we trim their input to be an actual
NULL value to avoid storing empty strings.
I am performing the
TRIM operations outside of
DECLARE @Test1 varchar(16) = ' ' IF LTRIM(RTRIM(ISNULL(@Test1,''))) = '' BEGIN SET @Test1 = NULL END SELECT @Test1
This appropriately returns a true
NULL value. Now let's place
ISNULL on the outside:
DECLARE @Test2 varchar(16) = ' ' IF ISNULL(LTRIM(RTRIM(@Test2)),'') = '' BEGIN SET @Test2 = NULL END SELECT @Test2
This also returns a
NULL value. Both work well for the intended usage, but I'm curious if there is any difference to how the SQL query optimizer handles this?