oracle: How does one code a matrix report in SQL?

Answer 1

SELECT  *
  FROM  (SELECT job,
                sum(decode(deptno,10,sal)) DEPT10,
                sum(decode(deptno,20,sal)) DEPT20,
                sum(decode(deptno,30,sal)) DEPT30,
                sum(decode(deptno,40,sal)) DEPT40
           FROM scott.emp
       GROUP BY job)
ORDER BY 1;

JOB           DEPT10     DEPT20     DEPT30     DEPT40
--------- ---------- ---------- ---------- ----------
ANALYST                    6000
CLERK           1300       1900        950
MANAGER         2450       2975       2850
PRESIDENT       5000
SALESMAN                              5600