java - hibernate - 如何 JoinColumn 一个 EmbeddedId

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，但具有相同的架构，因为每个图书馆都必须有自己的数据库。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，仍然记下它们各自的 ID 并将它们映射到它们的库 ID。

这里是我希望结构化的表:书- book_id- library_id- 标题- shelf_id架子- shelf_id- library_id- book_id- 描述

我有这些模型:

@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;
}

但是我得到了这个异常(exception):

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

我试过使用@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]

有什么帮助吗？

谢谢!

Answer 1

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

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