嵌套n： m属性JPA

Question

我在一个项目中有一个奇怪的需求。加入两个n： m属性表（我将用虚拟属性呈现行为）。

1. 第一表（idPlace、idAddress、idSchool、wage）加入1:m

当然，我有表地方，地址，学校，企业与他们各自的ID，获取，集合和属性在实体类中实现。

代码：

位置

@Entity
@Table(name = "Place")
public class Place implements Serializable {

/**
 * 
 */
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "idLine")
private Long idLine;

@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "pk.place")
private List<FirstTable> firstTables;
}

地址

@Entity
@Table(name = "Address")
public class Address implements Serializable {

/**
 * 
 */
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "idAddress")
private Long idAddress;

@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "pk.address")
private List<FirstTable> firstTables;
}

学校

@Entity
@Table(name = "School")
public class School implements Serializable {

/**
 * 
 */
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "idSchool")
private Long idSchool;

@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "pk.school")
private List<FirstTable> firstTables;
}

第一桌

@Entity
@Table(name = "FirstTable")
@AssociationOverrides({ @AssociationOverride(name = "pk.school", joinColumns = @JoinColumn(name = "idSchool")),
    @AssociationOverride(name = "pk.address", joinColumns = @JoinColumn(name = "idAddress")),
    @AssociationOverride(name = "pk.place", joinColumns = @JoinColumn(name = "idPlace")) })
public class FirstTable implements Serializable {

/**
 * 
 */
private static final long serialVersionUID = 1L;

@EmbeddedId
protected FirstTablePK pk = new FirstTablePK();
 }

FirstTablePK

@Embeddable
public class FirstTablePK implements Serializable{

/**
 * 
 */
private static final long serialVersionUID = 1L;
@ManyToOne
private Address address;
@ManyToOne 
private Place place;
@ManyToOne 
private School school;
}

上面提到的表和联接工作得很好。现在我想把第一个表和第二个表连接起来。

企业号

@Entity
@Table(name = "Enterprise")
public class Enterprise implements Serializable {

private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "idEnterprise")
private Long idEnterprise;

现在，对于第二个表，我遵循了相同的逻辑来连接到企业。对于与第一个表的连接，我尝试了以下方法：

@Entity
@Table(name = "SecondTable")
@AssociationOverrides({
        @AssociationOverride(name = "pk.firstTable", joinTable = @JoinTable(
                name = "FirstTable", inverseJoinColumns = {
                @JoinColumn(name = "idSchool", referencedColumnName = "idSchool"),
                @JoinColumn(name = "idAddress", referencedColumnName = "idAddress"),
                @JoinColumn(name = "idPlace", referencedColumnName = "idPlace") })),
        @AssociationOverride(name = "pk.enterprise", joinColumns = @JoinColumn(name = "idEnterprise")) })
public class SecondTable implements Serializable{}

我的注释中有些东西不起作用，我试图做一个inverseJoin到FirstTable表。编译显示此错误：

"org.hibernate.AnnotationException: A component cannot hold properties split into 2 different tables"

我试图提供一个MV示例。提前谢谢，我真的需要你的帮助。

Answer 1

几个小时后，经过多次尝试，我才设法解决了这个问题。事实上，解决方案比我最初想的要简单得多。

这是：

 @AssociationOverride(name = "pk.firstTable", joinColumns = {
            @JoinColumn(name = "idSchool"),
            @JoinColumn(name = "idAddress"),
            @JoinColumn(name = "idPlace") }),
    @AssociationOverride(name = "pk.enterprise", joinColumns = @JoinColumn(name = "idEnterprise")) })