Question

情况：我有一个masterDB和一个library1DB和library2DB。

library1DB和library2DB是两个独立的数据库，但具有相同的模式，因为每个库必须拥有自己的数据库。现在我们有了一个masterDB，这是所有库（library1DB和library2DB）中所有数据的聚合版本，仍然记录它们各自的id并将它们映射到它们的库id。

这是我希望我的表格结构化：书 - book_id - library_id - 标题 - shelf_id 架 - shelf_id - library_id - book_id - 说明

我有这些模特：

@Entity
public class Book {

    @EmbeddedId
    private BookKey bookKey;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumns({
            @JoinColumn(name = "SHELF_ID", referencedColumnName = "SHELF_ID"),
            @JoinColumn(name = "LIBRARY_ID", referencedColumnName = "LIBRARY_ID")
    })
    private ObjectA objectA;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumns({
            @JoinColumn(name = "ANOTHER_ID", referencedColumnName = "ANOTHER_ID"),
            @JoinColumn(name = "LIBRARY_ID", referencedColumnName = "LIBRARY_ID")
    })
    private ObjectB objectB;    

    @Column
    private String title;

}

@Embeddable
public class BookKey implements Serializable {
    @Column(name = "BOOK_ID")
    private long bookId;
    @Column(name = "LIBRARY_ID")
    private long libraryId;
}

但我得到了这个例外：

Caused by: org.hibernate.MappingException: Repeated column in mapping for entity: Book column: library_id (should be mapped with insert="false" update="false")

我尝试使用@IdClass而不是@Embeddable和@EmbeddedId，我得到了这个：

Caused by: org.hibernate.DuplicateMappingException:  Table [book] contains physical column name [libraryId] represented by different logical column names: [libraryId], [LIBRARY_ID]

任何帮助？

谢谢！

Answer 1

您应该为第二个映射列insert="false", update="false"添加library_id。试试这个：

@JoinColumn(name = "LIBRARY_ID", referencedColumnName = "LIBRARY_ID",
            insertable = false, updatable = false)

Answer 2

我遇到了同样的问题。如果你添加insert =＆＃34; false＆＃34;，update =＆＃34; false＆＃34;只有一个，你会得到一个例外，说明你混合了可写和不可写，并且这是不允许的。以下作品：

我使用 @PrimaryKeyJoinColumns 解决了它，试试这个（来自另一个例子）：

@ManyToOne
@PrimaryKeyJoinColumns(value = {
    @PrimaryKeyJoinColumn(name = "country_code", referencedColumnName = "country_code"),
    @PrimaryKeyJoinColumn(name = "zip_code", referencedColumnName = "code")
})
private Zip zip;

@ManyToOne
@PrimaryKeyJoinColumns(value = {
    @PrimaryKeyJoinColumn(name = "country_code", referencedColumnName = "country_code"),
    @PrimaryKeyJoinColumn(name = "state_code", referencedColumnName = "state_code"),
    @PrimaryKeyJoinColumn(name = "city_name", referencedColumnName = "name")
})
private City city;

来自Hibernate throws AnnotationException on column used by multiple overlapping foreign keys

hibernate - 如何JoinColumn一个EmbeddedId

2 个答案: