One- way Associations(单向关联) a class can contain more than one association with another class(一个类和另一个类可以有多 个关联) Flight ilot coPilot Pilot
17 One-way Associations (单向关联) • A class can contain more than one association with another class (一个类和另一个类可以有多 个关联) Pilot Flight -pilot -coPilot
Two- way Associations(双向关联) a two-way association indicates bi-directional navigation between objects of two classes 双向关联中每个类都有另外一个类的对象的引用 Course Student courses students 18
18 Two-way Associations(双向关联) • A two-way association indicates bi-directional navigation between objects of two classes. – 双向关联中每个类都有另外一个类的对象的引用。 Course Student -courses -students