Question

我的映射OneToMany有问题。我的例外是 org.hibernate.MappingException：实体映射中的重复列：com.lcdut.model.SubjectsModel column：groups（应使用insert =＆＃34映射; false＆＃34; update =＆＃34; false＆＃34;）< / p>

如果我使用udpatetable或插入false，那就是同样的问题（（

@Entity
@Table(name = "subjects")
public class SubjectsModel {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;
    @Column(name = "groups")
    private int groups;
    ...........
    @ManyToOne
    @JoinColumns({
            @JoinColumn(name = "groups", referencedColumnName = "id_group")
    })
    private StudentsModel studentsModel;
    ........
}

@Entity
@Table(name = "students")
public class StudentsModel {
    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    @Basic
    @Column(name = "pib")
    private String pib;
    @Basic
    @Column(name = "id_group")
    ........
    @OneToMany(mappedBy = "studentsModel")
    private Set<SubjectsModel> subjects;
}

Answer 1

@Column(name = "groups")
private int groups;
...........
@ManyToOne
@JoinColumns({
    @JoinColumn(name = "groups", referencedColumnName = "id_group")
})
private StudentsModel studentsModel;
........

这两个字段由同一列映射。您不需要private int groups;。删除它，一切都会工作。

Answer 2

如果我理解正确的方法，它应该是1：n-relation，它应该像下面这样工作（列/外键studentid必须作为数据库中的int存在）：

    @Entity
    @Table(name = "subjects")
    public class SubjectsModel {
        @Id
        @GeneratedValue(strategy = GenerationType.AUTO)
        private int id;

        @ManyToOne
        @JoinColumn(name = "studentsid")
        private StudentsModel studentsModel;
        ........
    }

    @Entity
    @Table(name = "students")
    public class StudentsModel {
        @Id
        @Column(name = "id")
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private int id;
        @Basic
        @Column(name = "pib")
        private String pib;
        @OneToMany(mappedBy = "studentsModel")
        private Set<SubjectsModel> subjects;
    }

使用@ManyToOne hibernate-mapping，引用列无法正常工作

2 个答案: