Hibernate @OneToMany没有单独的连接表

Question

请考虑以下数据库架构:

create table UserGroup ( id int not null auto_increment, name varchar(200),
    primary key(id));
create table User ( id int not null auto_increment, name varchar(200),
    groupId int not null, primary key(id));

User.groupId = UserGroup.id,因此用户只能是一个组的成员,但用户组可以存在许多用户.好到目前为止,让我们在Hibernate中创建实体.这是User:

@Entity
@Table(name = "User")
public class User {

    @Id
    @Column(name="id", nullable = false)
    private Integer id;

    @Column(name="name", length = 200, nullable = true)
    private String name;

    @ManyToOne(fetch=FetchType.EAGER)
    @JoinColumn(name = "groupId", nullable = false, insertable=false, updatable=false)
    @ForeignKey(name="FK_GroupId")
    private UserGroup userGroup;

    /* Getters, Setters, toString, equals & hashCode */
}

这是UserGroup:

@Entity
@Table(name = "UserGroup")
public class UserGroup {

    @Id
    @Column(name="id", nullable = false)
    private Integer id;

    @Column(name="name", length = 200, nullable = true)
    private String name;

    @OneToMany(fetch=FetchType.EAGER)
    private List<User> users;

    /* Getters, Setters, toString, equals & hashCode */
}

现在我会收到一个错误,"Table mydb.usergroup_user' doesn't exist"因为它需要一个连接表.由于与该应用程序将替换的其他应用程序的互操作性,我的数据结构"一成不变",因此我不会进行连接表.此外,它不应该是必需的.我该如何制作一个List<User> users简单的用户列表User.groupId == UserGroup.Id？

Answer 1

我认为你需要mappedBy="UserGroup"在@OneToMany注释中.