CREATE TABLE SC (SNO CHAR (6) NOT NULL, CNO CHAR(6) NOT NULL. GRADE DEC(4,1) DEFAULT NULL, PRIMARY (SNO,CNO), FOREIGE KEY(SNO) REFERENCES STUDENT ON DELETE CASCADE, FOREIGN KEY(CNO) REFERENCES COURSE ON DELETE RESTRICT);CREATE TABLE SC (SNO CHAR(6) NOT NULL, CNO CHAR(6) NOT NULL, GRADE DEC(4,1) DEFAULT NULL, PRIMARY (SNO,CNO), FOREIGE KEY(SNO) REFERENCES STUDENT ON DELETE CASCADE, FOREIGN KEY(CNO) REFERENCES COURSE ON DELETE RESTRICT);