要在另一個實體中引用的組合鍵的一個ID

Question

• 表1只有兩列形成組合鍵。
• 表2 id列正在生成。
• Table1的一個屬性的值我正在提供，第二個屬性我需要它來拾取Table2的生成值。 這裏是我有這麼遠

複合主鍵：

public class PKClass implements Serializable 
{ 
    private static final long serialVersionUID = -2092390836751020965L; 
    public PKClass(){} 
    public PKClass(long actId, long actAttId){ 
     this.actvId = actId; 
     this.actvAtId = actAttId; 
    } 

    private long actvId; 
    private long actvAtId; 
    // getters, setters, equals, hashcode 
} 

實體1類：

@Entity @Table(name = "Table1") 
@IdClass(PKClass.class) 
public class AtLinkData implements Serializable 
{ 
    @Id @Column(name = "ACT_ID", nullable = false) 
    private long actvId; 
    @Id @Column(name = "ACT_AT_ID") 
    private long actvAtId; 
    @OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER, , mappedBy = "atLinkData") 
    @JoinColumn(name = "ACT_AT_ID") 
    private AtData atData; 
    // getters, setters 
} 

實體2類：

@Entity @Table(name = "Table2") 
public class AtData implements Serializable 
{ 
    @TableGenerator(name = "somename", table = "sometable", pkColumnName = "somecolumn", valueColumnName = "valuename", pkColumnValue = "Table2", allocationSize = 1) 
    @Id @GeneratedValue(strategy = GenerationType.TABLE, generator = "somename") 
    @Column(name = "ACT_AT_ID") 
    private Long id; 
    // other variables 
    @OneToOne(fetch = FetchType.LAZY) 
    @JoinColumn(name = "ACT_AT_ID") 
    private AtLinkData atLinkData; 
    // getters setters 
} 

我有一直在嘗試不同的事情，但通過上面的代碼，我得到了婷錯誤：

Caused by: org.hibernate.MappingException: broken column mapping for: atLinkData.id of: com.test.database.AtData 

Answer 1

這是我如何解決它：

AtLinkData.java

@Id 
@GeneratedValue(generator = "foreignGenerator") 
@org.hibernate.annotations.GenericGenerator(name = "foreignGenerator", strategy = "foreign", parameters = @Parameter(name = "property", value = "atData")) 
@Column(name = "ACT_AT_ID") 
private long actvAtId; 

@OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER) 
@JoinColumn(name = "ACT_AT_ID",insertable=false,updatable=false) 
private AtData atData; 
// getters, setters 

AtData.java

@OneToOne(fetch = FetchType.LAZY, mappedBy="atData") 
private AtLinkData atLinkData; 

謝謝@CycDemo爲您的幫助。

Answer 2

@OneToOne（的mappedBy = 「活動促銷」） 使用JoinColumns標註不JoinColumn。 AtData實體

@OneToOne(fetch = FetchType.LAZY) 
@JoinColumns({ 
    @JoinColumn(name = "ACTVID", referencedColumnName = "ACTVID"), 
    @JoinColumn(name = "ACTVATID", referencedColumnName = "ACTVATID") 
}) 
private AtLinkData atLinkData; 

數據庫表，你必須添加兩個外鍵列ACTVID和ACTVATID。

更新

如果你不能在Table 2添加新列，在AtData實體，不AtLinkData使用mappedBy屬性。嘗試如下。

AtLinkData.java

@OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER) 
@JoinColumn(name = "ACT_AT_ID") 
private AtData atData; 

AtData.java

@OneToOne(fetch = FetchType.LAZY, mappedBy="atData") 
private AtLinkData atLinkData;