Isnull function in SQL SERVER

Isnull function

Any arthimetic operation with null results in null. Hence whenever you have to perform arithmetic operations on a column containing null use the function “ISNull”

DEPT TABLE

EMP TABLE

Display empno,ename, sal, comm along with total and annual salary

select empno,ename,sal,comm ,sal+isnull(comm,0),(sal+isnull(comm,0))*12 from emp

OR BY USING COL ALIAS

select empno,ename,sal,comm ,sal+isnull(comm,0) AS "TOTAL SALARY",(sal+isnull(comm,0))*12 AS "ANNUAL SALARY"from emp