[英]JPA / Hibernate unidirectional one-to-one mapping with shared primary key
[英]how to properly set up hibernate unidirectional one-to-one mapping
我有兩個表在列上具有one-to-one
映射。 我想使用注釋設置unidirectional one-to-one
休眠映射,因為我希望能夠從聯接表中獲取結果,但不想對子表進行外部約束檢查。
這是我的快速代碼。
@Entity
@Table(name = "student")
public class student {
// primary key and other column definition here..
@OneToOne(cascade = CascadeType.ALL)
@JoinColumn(name="address_id")
private Address address;
// getters and //setters
}
@Entity
@Tale(name = "address")
public class address {
@Id
@GeneratedValue(generator = "hibernate-uuid")
@GenericGenerator(name = "hibernate-uuid", strategy = uuid")
@Column(name = "id", unique = true, length = 36, nullable = false)
private String id;
@Column(name="address_id")
private String address_id;
// getters and setters
}
當我嘗試插入學生時(但不是地址),以上給出了以下異常。
Caused by: org.hibernate.AnnotationException: A Foreign key refering com.test.Student from com.test.Address has the wrong number of column. should be 2
我在這里做錯了什么?
首先,在student
課堂中將層疊類型更改為REFRESH(最好將其刪除)。 然后,如果它是單向的,則意味着另一部分將一無所知。 因此,您應該將referenceColumnName
添加到您的@OneToOne
@OneToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "PK_OF_THE_OTHER_TABLE", referencedColumnName = "CURRENT_TABLE_COLUMN_REFERENCE",
nullable = false, insertable = false, updatable = false)
@JoinColumn(name = "PK_OF_THE_OTHER_TABLE", referencedColumnName = "CURRENT_TABLE_COLUMN_REFERENCE",
nullable = false, insertable = false, updatable = false)
@JoinColumn(name = "PK_OF_THE_OTHER_TABLE", referencedColumnName = "CURRENT_TABLE_COLUMN_REFERENCE",
nullable = false, insertable = false, updatable = false)
@JoinColumn(name = "PK_OF_THE_OTHER_TABLE", referencedColumnName = "CURRENT_TABLE_COLUMN_REFERENCE",
nullable = false, insertable = false, updatable = false)
通過此實現,您將不需要更新其他部分,而是可以加入並獲取所需的信息。
更新 PK_OF_THE_OTHER_TABLE
是address
表的主鍵。 CURRENT_TABLE_COLUMN_REFERENCE
也是您的外鍵(當前表的字段指向address
表)-我假設您將一對一關系放在Student
實體中。
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