Hi,

Identity has been set (-1, 1) that means first row will start with -1 and there will be 1 increment in subsequesnt rows so the answer should be

-1, 0,...

When you cast(blank('') as int), it returns 0. so when you compare 0 with 0 nullif returns NULL.

declare @a smallint

set @a= 0

select nullif(@a,0)

Ans: NULL