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锁定老帖子 主题：关于关联的两个表之间的批量添加数据错误
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发表时间：2003-10-16
两个类如下:
package com.getdown.hibernate;
public class Post {
private Long id;
private String title;
private String content;
private User owner;
public Post(); {
}
public Post(String title); {
this.title = title;
}
public Long getId(); {
return id;
}
private void setId(Long long1); {
id = long1;
}
public String getTitle(); {
return title;
}
public void setTitle(String string); {
title = string;
}
public String getContent(); {
return content;
}
public void setContent(String string); {
content = string;
}
public User getOwner(); {
return owner;
}
public void setOwner(User user); {
owner = user;
}
public boolean equals(Object obj); {
if(!(obj instanceof Post););
return false;
return ((Post);obj);.getId();.equals(id);;
}
}
package com.getdown.hibernate;
import java.util.HashSet;
import java.util.Set;
public class User {
private Long id;
private String mail;
private String password;
private String nick;
private Set posts;
private User(); {}
public User(Long id); {
id = id;
posts = new HashSet();;
}
public User(String nick); {
this.nick = nick;
posts = new HashSet();;
}
public Long getId(); {
return id;
}
private void setId(Long id); {
id = id;
}
public String getMail(); {
return mail;
}
public void setMail(String string); {
mail = string;
}
public String getPassword(); {
return password;
}
public void setPassword(String string); {
password = string;
}
public String getNick(); {
return nick;
}
public void setNick(String string); {
nick = string;
}
public Set getPosts(); {
return posts;
}
public void setPosts(Set set); {
posts = set;
}
public boolean equals(Object obj); {
if(!(obj instanceof User););
return false;
return ((User);obj);.getId();.equals(id);;
}
}
两个配置文件如下: <?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
<class
name="com.getdown.hibernate.Post"
table="POST"
dynamic-update="false"
dynamic-insert="false"
>
<id
name="id"
column="POST_ID"
type="java.lang.Long"
>
<generator class="identity">
</generator>
</id>
<property
name="title"
type="java.lang.String"
update="true"
insert="true"
column="TITLE"
/>
<property
name="content"
type="java.lang.String"
update="true"
insert="true"
column="CONTENT"
/>
<many-to-one
name="owner"
class="com.getdown.hibernate.User"
cascade="all"
outer-join="auto"
update="true"
insert="true"
column="OWNER_ID"
/>
</class>
</hibernate-mapping>
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
<class
name="com.getdown.hibernate.User"
table="USER"
dynamic-update="false"
dynamic-insert="false"
>
<id
name="id"
column="USER_ID"
type="java.lang.Long"
>
<generator class="identity">
</generator>
</id>
<property
name="mail"
type="java.lang.String"
update="true"
insert="true"
column="E_MAIL"
/>
<property
name="password"
type="java.lang.String"
update="true"
insert="true"
column="PASSWORD"
/>
<property
name="nick"
type="java.lang.String"
update="true"
insert="true"
column="NICK_NAME"
/>
<set
name="posts"
lazy="true"
cascade="save-update"
inverse="true"
sort="unsorted"
order-by="POST_ID"
>
<key
column="OWNER_ID"
/>
<one-to-many
class="com.getdown.hibernate.Post"
/>
</set>
</class>
</hibernate-mapping>
测试类: public class UserHibernate {
public static void main(String[] args); throws Exception {
Configuration cfg = new Configuration();.addClass(User.class);.addClass(Post.class);;
SessionFactory sessions = cfg.buildSessionFactory();;
Session session = sessions.openSession();;
Set set = new HashSet();;
User user = (User); session.find("from User user where user.id='1'");.get(0);;
for (int i = 0; i < 10; i++); {
Post post = new Post("a");;
post.setOwner(user);;
// session.save(post);;
set.add(post);;
}
user.setPosts(set);;
session.save(user);;
session.flush();;
session.close();;
}
}
这样两个表数据都可以数据都能添加 但是两个表之间的关联字段 即post里面的 OWNER_ID 为 null 抛出异常 net.sf.hibernate.HibernateException: identifier of an instance of com.getdown.hibernate.User altered from 1 to null 哪位大虾帮一下 呵呵 声明：ITeye文章版权属于作者，受法律保护。没有作者书面许可不得转载。
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发表时间：2003-10-16
引用 session.save(user); 这句是不需要的，Session.save()其实就是insert，对于在同一个Session中载入并作了修改而需要保存的对象只需要Session.flush()就行了。 加上事务处理。 引用 <many-to-one name="owner" class="com.getdown.hibernate.User" cascade="all" outer-join="auto" update="true" insert="true" column="OWNER_ID" /> many-to-one的cascade设为"all"是不对的，改为"save-update"好了。 |
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发表时间：2003-10-16
这样改过改完了 还是一样的错误...
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发表时间：2003-10-16
引用 private void setId(Long id) { id = id; }   
你的程序中还有好几个类似的错误！！！！！！ |
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发表时间：2003-10-16
极端不好意思 我以后一定仔细看完再发
浪费了yeh220那么多时间 抱歉 |
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