مثال محبوك عن Decode

CREATE a matrix query to display the job ,the salary for that job based on department number, and the total salary for that job ,for departments 10 , 50 ,80 , 90

SELECT JOB_ID , 
sum (case department_id when 20 then (salary) end) "20" ,
sum (case department_id when 50 then(salary) end ) "50",
sum (case department_id when 80 then (salary) end) "80",
sum (case department_id when 90 then (salary) end ) "90" , 
sum (salary) total
FROM employees GROUP BY job_id

SELECT job_id , 
Sum (decode ( department_id , 20 , salary) )"20",
Sum (decode ( department_id , 90 , salary) )"90",
Sum (decode ( department_id , 80 , salary) )"80",
Sum (decode ( department_id , 50 , salary) )"50",
Sum (salary) “Total”
FROM employees GROUP BY job_id