What is NullIf() in Sql Srever

NullIf(expression1,expression2)

If both expressions values are same then return Null otherwise return first expression values.


create table Store
(
 Id int identity(1,1),
 Store varchar(50),
 Actual int,
 Goal int
)

insert into Store(Store,Actual,Goal) values('StoreA',50,50),('StoreB',40,50),('StoreC',25,30)

Id Store Actual Goal
1 StoreA 50         50
2 StoreB 40         50
3 StoreC 25         30

Query -

select Store, nullif(Actual,Goal) 'CheckNullIf' from Store

Output -

Store CheckNullIf
StoreA NULL
StoreB 40
StoreC 25