INSERT INTO DEPT(DEPTID, DEPTNAME) VALUES
        ( 1, 'DEPT1'),
        (2, 'DEPT2'),
        (3,'DEPT2'),
        (4,'DEPT4'),
        (5,'DEPT4'),
        (6,'DEPT6');

INSERT INTO WORK (WORKID, DEPTID, SAL,CITYID) VALUES
   (  100,1,1000,10),
   (  100,2,2000,10),
   (  200,1,2500,20),
   (  300,3,1000,10),
   (  300,6,3000,10),
   (  300,6,1000,30)
;

Cityid  deptname count avg-sal
10       dept1    1     1000
10       dept2    2     1500
10       dept4    0      0
10       dept6    1      3000
Grandtotal        3      2333.33