Get Difference Between Two Rows

 

 

Employee table have EmployeeID, and his salary for each month
 

EmpID	EmpName	Salary	month
1	Sally	2000	2
1	Sally	2500	3
2	Noor	3200	1
2	Noor	3250	2

 

 

to get difference between salary for EmpID = 1 for month 2 , 3



 

SELECT empName as name , salary  - (
                                                                  SELECT  salary
                                                                  FROM Employee
                                                                  WHERE month = 2
                                                               ) as Diff_Salary
from Employee 
 

where month = 3

 

and   EmpID  =  1

 

 

the Result