CREATE TABLE For_Test(ID int not null,Name varchar(255),Amount decimal(18,2))
   INSERT INTO For_Test VALUES (1,'A',220),(2,'B',340),(3,'C',540)
   ,(4,'D',780)

--I just want to add amount of ID 1,2 and 3 excluding 4. 
  SELECT SUM(Amount) FROM For_Test WHERE ID in (1,2,3)

--Different select statement but same result
  SELECT SUM(Amount) FROM For_Test WHERE ID <> 4
--Yet a 3rd way
   SELECT SUM(Amount) FROM For_Test WHERE ID < 4
--Yet a 4th way - using MOD function
   SELECT SUM(Amount) FROM For_Test WHERE ID % 4 <> 0;
Result:
(No column name)
1100.00