Hibernate:如何通过注释在一个联接表中联接3个表? [英] Hibernate : How to Join 3 tables in one join table by Annotation?

问题描述

我有一些角色，用户和应用程序 我想创建该表的映射休眠模式:

I have some roles, users and applications I want to create a mapping hibernate of this table :

CREATE TABLE role_application_user (
  role_identifier INTEGER not null,
  application_identifier INTEGER not null,
  user_identifier INTEGER not null,
  KEY FK_role_identifier (role_identifier),
  KEY FK_application_identifier(application_identifier),
  KEY FK_user_identifier (user_identifier),
  CONSTRAINT FK_role_identifier FOREIGN KEY (role_identifier) REFERENCES role (identifier),
  CONSTRAINT FK_application_identifier FOREIGN KEY (application_identifier) REFERENCES application (identifier),
  CONSTRAINT FK_user_identifier FOREIGN KEY (user_identifier) REFERENCES users (login)
);

对于一个应用程序，一个角色可以有许多用户，而一个用户可以有许多角色.

for an application, a role can have many users and a user can of many roles.

我尝试此映射:

Application.java

Application.java

@JoinTable(name = "role_application_user",
           joinColumns = @JoinColumn(name = "application_identifier"),
           inverseJoinColumns = @JoinColumn(name = "user_identifier"))
@MapKeyJoinColumn(name = "role_identifier")
@ElementCollection
private Map<Role, User> userByRole = new HashMap<>();

不幸的是，这在我的情况下不起作用，因为在Java中，Map的键必须是唯一的.

Unfortunately, this is not working in my case because in java, the key of a Map must be unique.

通过这种映射，我们只有一个角色和一个应用程序的用户.

With this mapping, we can have only one user for a role and an application.

推荐答案

尝试此实现:

@Entity
public class User{
    @OneToMany
    private List<RoleInApplication> rolesInApplications;
}

@Entity
public Class Role{
   @OneToMany
    private List<RoleInApplication> rolesInApplications;
}

@Entity
public class RoleInApplication{
    @ManyToOne
    private User user;
    @ManyToOne
    private Role role;
    @ManyToOne
    private Application application;
}

@Entity
public Class Application{
   @OneToMany
   private List<RoleInApplication> rolesInApplications;
}

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