Right Outer Join course natural right outer join prereg course id title dept name credits prereq id BI0-301 Genetics Biology 4 BIO-101 CS-190 Game Design Comp.Sci. 4 CS-101 CS-347 null null null CS-101 Database System Concepts-6th Edition 4.7 ©Silberschat乜，Korth and SudarshanDatabase System Concepts - 6 4.7 ©Silberschatz, Korth and Sudarshan th Edition Right Outer Join course natural right outer join prereq