Relationships Between Objects（对象之间的关系 ）
XPO supports three types of relationships between objects. The type of a relationship that is created depends upon how related objects are defined.
XPO支持对象之间的三种类型的关系。创建的关系类型取决于相关对象的定义方式。
- One-to-Many Relationships（一对多关系）
- One-to-One Relationships（一对一的关系）
- Many-to-Many Relationships（多对多关系）
One-to-Many Relationships（一对多关系）
A one-to-many relationship is the most common type of relationship. In this relationship, a persistent object of type A can have many associated objects of type B, but an object of type B can have only one associated object of type A.
一对多关系是最常见的关系类型。在这种关系中，A类型的持久对象可以有许多B类型的关联对象，但B类型的对象只能有一个A类型的关联对象。
For example, orders
标签：02,Relationships,relationship,05,对象,关系,Many,type From： https://blog.csdn.net/thomastang200912_126/article/details/141449381