java - Hibernate 通过非 id 列关联两个实体

Question

我面临以下情况:

Table Store: |Id|...|CostCenterNumber|

Table MasterData: |dennskdnr|...|

我当前的映射如下所示

@Entity
@Table(name = "Store")
public class Store implements Identifiable {
[...]
    @OneToOne(optional = true)
    @JoinColumn(name = "CostCenterNumber", insertable = false, updatable = false)
    private MasterData masterData;
[...]
}

和

@Entity
@Table(name = "MasterData")
public class MasterData {
[...]
    @OneToOne(optional = true)
    @JoinColumn(name = "dennskdnr")
    private Store store;
[...]
}

导致我出现以下异常:

org.hibernate.TypeMismatchException: Provided id of the wrong type for class datamodel.Store. Expected: class java.lang.String, got class java.lang.Integer

Answer 1

以下是关联的映射方式:

@Entity
@Table(name = "Store")
public class Store implements Identifiable {

    @OneToOne(optional = true)
    @JoinColumn(name = "CostCenterNumber", referencedColumnName="dennskdnr")
    private MasterData masterData;

}

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

    @OneToOne(optional = true, mappedBy = "masterData")
    private Store store;

}

请记住:在双向关联中，始终有一个所有者方(定义关联的映射方式)和一个反方(使用必须使用 mappedBy 属性来表示:我是反方，查看另一个实体中的“masterData”属性就知道这个关联是如何映射的。