Question

我正在使用Hibernate 4.1.7 Java和Spring，使用MySql。

我有一个Publication类，它是抽象的，有3个子类，还有一个Page类，它也是抽象的，有2个子类。

在出版物中有一个List，在页面i中有一个出版物，所以它是一个常见的OneToMany / ManyToOne双向关系，但由于我需要对页面进行排序，我使用的是交叉表，如下所示：

// Publication.java
@OneToMany(fetch=FetchType.LAZY)
@JoinTable(name="publication_pages",
            joinColumns=@JoinColumn(table="publication_pages", name="pub_id", referencedColumnName="id"),
            inverseJoinColumns=@JoinColumn(table="publication_pages", name="pg_id", referencedColumnName="id"))
@OrderColumn(name="i")
public List<Page> getPages() {
    return pages;
}

// Page.java

@ManyToOne
@JoinTable(name="publication_pages",
        joinColumns=@JoinColumn(table="publication_pages", name="pg_id", referencedColumnName="id", insertable=false, updatable=false),
        inverseJoinColumns=@JoinColumn(table="publication_pages", name="pub_id", referencedColumnName="id", insertable=false, updatable=false))
public Publication getPublication() {
    return publication;
}

Hibernate不会抱怨注释，但是一旦我尝试调用getPages，它就会生成一个查询页面子类表上的pub_id的查询，而不是仅在交叉表中查找。

错误是：

com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'page1_.pub_id' in 'field list'
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1053)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4074)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4006)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2468)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2629)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2719)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2155)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2318)
at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeQuery(NewProxyPreparedStatement.java:76)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.hibernate.engine.jdbc.internal.proxy.AbstractStatementProxyHandler.continueInvocation(AbstractStatementProxyHandler.java:122)
at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
at $Proxy54.executeQuery(Unknown Source)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1897)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1698)
at org.hibernate.loader.Loader.doQuery(Loader.java:832)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:293)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:263)
at org.hibernate.loader.Loader.loadCollection(Loader.java:2094)
at org.hibernate.loader.collection.CollectionLoader.initialize(CollectionLoader.java:61)
at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:678)
at org.hibernate.event.internal.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:82)
at org.hibernate.internal.SessionImpl.initializeCollection(SessionImpl.java:1801)
at org.hibernate.collection.internal.AbstractPersistentCollection$4.doWork(AbstractPersistentCollection.java:524)
at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:212)
at org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:520)
at org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:125)
at org.hibernate.collection.internal.AbstractPersistentCollection$1.doWork(AbstractPersistentCollection.java:152)
at org.hibernate.collection.internal.AbstractPersistentCollection$1.doWork(AbstractPersistentCollection.java:139)
at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:212)
at org.hibernate.collection.internal.AbstractPersistentCollection.readSize(AbstractPersistentCollection.java:138)
at org.hibernate.collection.internal.PersistentList.isEmpty(PersistentList.java:121)

我做错了什么，或者是Hibernate错误，还是因为它在查询中执行了大量的联合而根本不可能？

TIA

编辑：这是hibernate生成的查询（我删除了所有不相关的列）：

Hibernate: 
select 
pages0_.pub_id as pub1_46_3_, 
pages0_.pg_id as pg2_43_3_, 
pages0_.i as i3_,
page1_.id as id42_0_, 
[...] 
page1_.pub_id as pub1_43_0_ [...]

from publication_pages pages0_ 
inner join ( 
  select id, [...] from page_fixed union select id, [...] from page_query 
) page1_

on pages0_.pg_id=page1_.id left outer join ( 
  select id, [...] from publication 
) publicatio2_ 
on page1_.pub_id=publicatio2_.id left where pages0_.pub_id=?

如您所见，它在连接中使用page1_.pub_id（就像pub_id在页面上一样）而不是pages0_.pub_id（在where子句中正确使用）。

这是在调用Publication.getPages（）。isEmpty（）

时发生的

Answer 1

也许，您可以向mappedBy添加@OneToMany并删除其@JoingTable。与OneToMany / ManyToOne的双向关系双方都不需要@JoingTable，您只需要在关系所有者处使用它。

Hibernate具有JoinTable的双向OneToMany和具有每个具体类的表的多态类

1 个答案: