java 休眠 - 如何加入一个 EmbeddedId 列

hibernate - how to JoinColumn an EmbeddedId

提问by villager

Situation: I have a masterDB and a library1DB and library2DB.

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

library1DB and library2DB are two separate database but has the same schema because each library must have their own database. Now we have a masterDB, this is an aggregated version of all the data in all libraries (library1DB and library2DB), still taking note of their respective ids and mapping them to their library id.

library1DB 和 library2DB 是两个独立的数据库，但具有相同的架构，因为每个库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。

Here's I want my tables to be structured: book - book_id - library_id - title - shelf_id shelf - shelf_id - library_id - book_id - description

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

I have these models:

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;
}

But I get this exception:

但我得到这个例外：

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

I've tried using @IdClass instead of @Embeddable and @EmbeddedId, and I got this:

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]

Any help?

有什么帮助吗？

Thanks!

谢谢！

回答by Alex

You should add insert="false", update="false"for the second mapped column library_id. Try this:

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

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

回答by Ben

I was getting the same problem. If you add insert="false", update="false" only to one, you will get an exception stating that you mixed writable and non-writables and that this is not allowed. The following works:

我遇到了同样的问题。如果仅将 insert="false", update="false" 添加到一个，您将收到一个异常，指出您混合了可写和不可写，这是不允许的。以下工作：

I solved it using the @PrimaryKeyJoinColumns, try this (from another example):

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

@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;

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

来自Hibernate 在多个重叠外键使用的列上抛出 AnnotationException