Relationship Sets A relationship is an association among several entities Example: 44553(Peltier) advisor 22222(Einstein) student entity relationship set instructor entity A relationship set is a mathematical relation among n>2 entities,each taken from entity sets {(e1,e2,.en)|e1∈E1,e2∈E2,,en∈Enl where (e1,e2,...,e)is a relationship ·Example: (44553,22222)∈advisor Database System Concepts-7th Edition 6.13 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 6.13 ©Silberschatz, Korth and Sudarshan th Edition Relationship Sets ▪ A relationship is an association among several entities Example: 44553 (Peltier) advisor 22222 (Einstein) student entity relationship set instructor entity ▪ A relationship set is a mathematical relation among n  2 entities, each taken from entity sets {(e1 , e2 , … en ) | e1  E1 , e2  E2 , …, en  En } where (e1 , e2 , …, en ) is a relationship • Example: (44553,22222)  advisor