Question

求助，jpa为含有复合主键如何建立一对多的关联

Answer 1

进行面向对象的分析，uer和role之间是双向多对多联系，使用JPA配置如下所示：
@Entity
public class User implements Serizlizable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
private String userName;
private String passWord;
@ManyToMany(cascade = CascadeType.ALL)
private List<Role> roles;
......
......
}

@Entity
public class Role implements Serizlizable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
private String role;
@ManyToMany(mappedBy = "roles")
private User user;
......
......
}

配置后，会在数据库中生存你想要的3个表。