我的数据库如下：tt_user和room：
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[tt_user]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [dbo].[tt_user]
GO
CREATE TABLE [dbo].[tt_user] (
[USER_ID] [int] IDENTITY (1, 1) NOT NULL ,
[NAME] [varchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,
[ROOM_ID] [int] NULL ,
CONSTRAINT [PK_user] PRIMARY KEY CLUSTERED
(
[USER_ID]
) ON [PRIMARY] ,
CONSTRAINT [FK_tt_user_room] FOREIGN KEY
(
[ROOM_ID]
) REFERENCES [dbo].[room] (
[ROOM_ID]
)
) ON [PRIMARY]
GO
|
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[room]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [dbo].[room]
GO
CREATE TABLE [dbo].[room] (
[ROOM_ID] [int] IDENTITY (1, 1) NOT NULL ,
[ADDRESS] [varchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,
CONSTRAINT [PK_room] PRIMARY KEY CLUSTERED
(
[ROOM_ID]
) ON [PRIMARY]
) ON [PRIMARY]
GO
XML文件如下：
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse - Hibernate Tools
-->
<hibernate-mapping>
<class name="One_To_Many.Room" table="room"
dynamic-update="true"
dynamic-insert="true"
schema="dbo" catalog="BlogOnline">
<id name="id" type="java.lang.Integer" >
<column name="ROOM_ID" />
<generator class="native"/>
</id>
<property name="address" type="java.lang.String">
<column name="ADDRESS" length="50" />
</property>
<set name="users"
table="tt_USER"
lazy="false"
inverse="true"
cascade="all">
<key column="ROOM_ID"/>
<one-to-many class="One_To_Many.User"/>
</set>
</class>
</hibernate-mapping>
|
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse - Hibernate Tools
-->
<hibernate-mapping>
<class name="One_To_Many.User" table="tt_user"
dynamic-update="false"
dynamic-insert="false"
schema="dbo" catalog="BlogOnline">
<id name="Id" type="java.lang.Integer" >
<column name="USER_ID" />
<generator class="native" />
</id>
<property name="name" type="java.lang.String">
<column name="NAME" length="50" />
</property>
<many-to-one name="room"
class="One_To_Many.Room"
cascade="none"
outer-join="auto"
update="true"
insert="true"
access="property"
column="ROOM_ID"
not-null="true"
/>
</class>
</hibernate-mapping>
|
Java代码如下：
package One_To_Many;
import java.util.HashSet;
import java.util.Set;
public class Room {
private long id;
private String address;
private Set users = new HashSet();
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public Set getUsers() {
return users;
}
public void setUsers(Set users) {
this.users = users;
}
}
|
package One_To_Many;
public class User {
private long Id;
private String name;
private Room room;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Room getRoom() {
return room;
}
public void setRoom(Room room) {
this.room = room;
}
public long getId() {
return Id;
}
public void setId(long id) {
Id = id;
}
}
|
测试代码如下：
package One_To_Many;
import java.sql.SQLException;
import javax.security.auth.login.Configuration;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Transaction;
import test.HibernateSessionFactory;
public class Test {
public static void main(String[] args) throws HibernateException, SQLException {
Session session = HibernateSessionFactory.getSession();
session.connection().setAutoCommit(true);
Room room = new Room();
room.setAddress("China-10-911");
User user1 = new User();
user1.setName("ivan");
User user2 = new User();
user2.setName("mada");
user1.setRoom(room);
user2.setRoom(room);
room.getUsers().add(user1);
room.getUsers().add(user2);
Transaction tx= (Transaction) session.beginTransaction();
session.save(room);
tx.commit();
session.close();
System.out.println("transaction ends");
}
}
|
出现的错误如下：
Exception in thread "main" org.hibernate.HibernateException: identifier of an instance of One_To_Many.Room was altered from 9 to 9
at org.hibernate.event.def.DefaultFlushEntityEventListener.checkId(DefaultFlushEntityEventListener.java:51)
at org.hibernate.event.def.DefaultFlushEntityEventListener.getValues(DefaultFlushEntityEventListener.java:150)
at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:106)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:195)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:76)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:26)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:985)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:333)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
at One_To_Many.Test.main(Test.java:45)
|
其中，我测试一次，from to 就增加一，我测试了九次，所以九有from 9 to 9！我刚学习hibernate不久，恳求banq和各位帮助一下，不胜感谢！