To see the difference between a person's salary and the average for his or her region.
SQL> SQL> drop table emp; Table dropped.-- from ww w . ja v a 2 s . co m SQL> create table emp( 2 empno Number(3) NOT NULL, 3 ename VARCHAR2(10 BYTE), 4 hireDate DATE, 5 orig_salary Number(8,2), 6 curr_salary Number(8,2), 7 region VARCHAR2(1 BYTE) 8 ); SQL> SQL> insert into emp values(1,'Alison',DATE '1996-03-21', 45000, NULL, 'E'); SQL> insert into emp values(2,'James',DATE '1978-12-12', 23000, 32000, 'W'); SQL> insert into emp values(3,'Celia',DATE '1982-10-24', NULL, 58000, 'E'); SQL> insert into emp values(4,'Robert',DATE '1984-01-15', 31000, NULL, 'W'); SQL> insert into emp values(5,'Linda',DATE '1987-07-30', NULL, 53000, 'E'); SQL> insert into emp values(6,'David',DATE '1990-12-31', 78000, NULL, 'W'); SQL> insert into emp values(7,'Jode',DATE '1996-09-17', 21000, 29000, 'E'); SQL> SQL> SELECT empno, ename, region, curr_salary, 2 orig_salary, 3 ROUND(AVG(orig_salary) OVER(PARTITION BY region)) 4 "Avg-group", 5 ROUND(orig_salary - AVG(orig_salary) OVER(PARTITION 6 BY region)) "Diff." 7 FROM emp 8 ORDER BY region, ename 9