描述了实体关系的概念、实体关系在Java中的建模规则、实体关系在数据库中的建模、掌握使用Hibernate实现一对一、一对多、多对多的关联映射的配置-Describes the concept of entity relationship, entity relationship modeling in Java, the rules in the database entity relationship modeling, master the use of Hibernate to achieve one to one, many, many to many association mapping configuration