Derived column in Sql Server:
CREATE TABLE Students(ID INT,
NAME VARCHAR(33),
M1 INT,
M2 INT,
M3 INT, 
TOTAL AS (M1+M2+M3) )--This is derived column
----- Insert data 
INSERT INTO Students values(1,'raju',67,78,85)
INSERT INTO Students values(2,'Kiran',77,58,55)
INSERT INTO Students values(3,'Ramu',87,78,45)
INSERT INTO Students values(4,'Rani',57,77,49)

SELECT * FROM Students
---Updations done on Derived Column
   UPDATE Students SET M1=0,M2=100,M3=99 WHERE ID=1