Query to calculate column value based upon another using CASE statement in SQL Server

Hi mahesh213,

You need to use CASE statement.

Refer below query.

SQL

DECLARE @Test AS TABLE(Id INT,Name VARCHAR(50),Salary INT)
INSERT INTO @Test VALUES(1,'a',10)
INSERT INTO @Test VALUES(2,'b',20)
INSERT INTO @Test VALUES(3,'c',30)
INSERT INTO @Test VALUES(4,'d',40)
INSERT INTO @Test VALUES(5,'e',50)

SELECT Id, [Name],
	CASE WHEN ([Name] = 'b' OR [Name] = 'd') AND ISNULL(Salary, 0) = 0  THEN 0
	WHEN [Name] = 'b' OR [Name] = 'd' THEN ISNULL(Salary, 0) - 3
	ELSE IsNull(Salary, 0) END AS Salary
FROM @Test

Output