/* 
 * 
 *
 * 
 */

create table workson3 (
        essn               char(9)            not null,
        pno                int                not null,
    primary key (essn, pno)
) ;


insert into workson3
(essn, pno)
values
('100000001', 12),   -- first group
('100000002', 12),

('100000002', 23),
('100000003', 23),

('100000003', 34),
('100000004', 34),

('100000004', 45),
('100000005', 45),

('100000005', 56),
('100000006', 56),

('100000006', 67),
('100000007', 67),

('100000007', 78),
('100000008', 78),

('100000008', 89),
('100000009', 89),

('100000009', 90),
('100000010', 90),

('100000006', 206),
('100000020', 206),

('100000020', 220),
('100000021', 220),

('100000021', 221),
('100000022', 221),

('100000022', 222),
('100000023', 222),

('100000023', 223),
('100000024', 223),

('100000031', 312),   -- second group
('100000032', 312),

('100000032', 323),
('100000033', 323),

('100000033', 334),
('100000034', 334),

('100000034', 345),
('100000035', 345),

('100000035', 356),
('100000036', 356),

('100000036', 367),
('100000037', 367);