hibernate 关于联合主键

摘要: hibernate 关于联合主键

-----------------------------映射文件----------------------------------------------

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="cn.gdpe.compositeKey" auto-import="true">
<class name="User">
<!-- 复合主键映射 -->
<composite-id name="keys">//联合主键对象与实体类定义的引用名必须一致
<key-property name="userName" type="string"></key-property>
<key-property name="address" type="string"></key-property>
</composite-id>
<property name="age" type="int"></property>
</class>

</hibernate-mapping>

-------------------------------联合主键类----------------------------------------------

package cn.gdpe.compositeKey;

import java.io.Serializable;

// 复合主键类
public class CompositeKeys implements Serializable{
private String userName;
private String address;
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}

}

------------------------------实体对象类---------------------------------

public class User {

// 名字跟地址，不会重复
private CompositeKeys keys;
private int age;

public CompositeKeys getKeys() {
return keys;
}
public void setKeys(CompositeKeys keys) {
this.keys = keys;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}

-----------------------------总结-----------------------------------------

联合主键 就是把需要设为主键的属性 提取出来 重写定义一个主键类（就是一个普通类） 联合主键作为此类的属性

在实体类中 引用该类 映射文件中如上设置。