CASE Query in SQL

 CREATE TABLE emp(id int , sal int);

insert into emp values(1,100);

insert into emp values(2,200);

insert into emp values(3,300);

insert into emp values(4,400);

insert into emp values(5,500);

insert into emp values(6,600);

insert into emp values(7,700);

insert into emp values(8,800);

insert into emp values(9,900);

insert into emp values(10,1000);

select * from emp;

Update emp set sal = 

Case  id When '1' THEN sal + 10 

         When '2' THEN sal + 20

       ELSE 

   sal

       END

        WHERE id IN('1', '2');