Java Hibernate（Spring JPA）：@ManyToOne JoinColumns（一个嵌入ID）为空

我没有看到我的错误，在研究了stackoverflow和Google之后，我认为代码应该是正确的。但是Hibernate（spring boot starter数据jpa 2.2.4）仍然用

null

填充join列

这是我的

OneToMany

课程：

@Entity
@Table(name = "tablea", schema = "")
public class TableAEntity implements Serializable {

    private static final long serialVersionUID = 7890327260188587351L;

    @EmbeddedId
    private MyId id;
    
    @OneToMany(cascade = ALL, mappedBy = "tableA", orphanRemoval = true, fetch = FetchType.LAZY)
    private List<TableBEntity> tableBentries;
    
    // Getter + Setter
}

@Embeddable
public class MyId implements Serializable {

    private static final long serialVersionUID = -8267953052238233498L;

    @Column(name = "id")
    private String id;

    @Column(name = "iddate")
    private Date iddate;

    @Column(name = "idint")
    private BigInteger idint;
    
    // Getter + Setter
}

@Entity
@Table(name = "tableB", schema = "")
public class TableBEntity implements Serializable {

    private static final long serialVersionUID = -4648090658471459969L;

    @Id
    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumns({
        @JoinColumn(name = "id", referencedColumnName = "id"),
        @JoinColumn(name = "iddate", referencedColumnName = "iddate"),
        @JoinColumn(name = "idint", referencedColumnName = "idint")
    })
    private TableAEntity tableA;
    
    // Some other attributes
    
    // Getter + Setter
}

最后是我的

manytone

课程：

@Entity
@Table(name = "tablea", schema = "")
public class TableAEntity implements Serializable {

    private static final long serialVersionUID = 7890327260188587351L;

    @EmbeddedId
    private MyId id;
    
    @OneToMany(cascade = ALL, mappedBy = "tableA", orphanRemoval = true, fetch = FetchType.LAZY)
    private List<TableBEntity> tableBentries;
    
    // Getter + Setter
}

@Embeddable
public class MyId implements Serializable {

    private static final long serialVersionUID = -8267953052238233498L;

    @Column(name = "id")
    private String id;

    @Column(name = "iddate")
    private Date iddate;

    @Column(name = "idint")
    private BigInteger idint;
    
    // Getter + Setter
}

@Entity
@Table(name = "tableB", schema = "")
public class TableBEntity implements Serializable {

    private static final long serialVersionUID = -4648090658471459969L;

    @Id
    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumns({
        @JoinColumn(name = "id", referencedColumnName = "id"),
        @JoinColumn(name = "iddate", referencedColumnName = "iddate"),
        @JoinColumn(name = "idint", referencedColumnName = "idint")
    })
    private TableAEntity tableA;
    
    // Some other attributes
    
    // Getter + Setter
}

正如您可能看到的，我希望将属性（

id

、

iddate

和

idit

）用作两个表中的组合primaray键

创建

tableEntity

对象时，我将几个

tablebenty

对象添加到

tableBentries

属性中。对于每个

tablebenty

，我将引用设置为

tableEntity

（属性

tableA

）。当然，

MyId

（属性

id

）对象被填充

保存

tableEntity

对象后，Hibernate还存储所有

tableBenty

，但

id

、

iddate

和

idit

（所有JoinColumn）字段均为

null

---

有什么想法吗？

我的

表格中的
@Id
似乎是问题的根源。如果我将它移动到另一个属性，它就会工作。
也许您可以使用“private MyId”作为列。我猜它会自动保存所有三个字段。