CREATE TABLE A (u0 INT UNSIGNED NOT NULL, 
                u1 INT UNSIGNED NOT NULL, 
                p1 INT UNSIGNED NOT NULL, 
                p2 INT UNSIGNED NOT NULL, 
                p3 INT UNSIGNED NOT NULL, 
                p4 VARCHAR(40), 
                UNIQUE u_u0_u1 (u0, u1));

INSERT INTO A (u0, u1, p1, p2, p3, p4) VALUES (0, 101, 201, 301, 302, "B1,C1,C2");
INSERT INTO A (u0, u1, p1, p2, p3, p4) VALUES (0, 102, 202, 302, 301, "B2,C2,C1");
INSERT INTO A (u0, u1, p1, p2, p3, p4) VALUES (103, 0, 203, 303, 303, "B3,C3,C3");
