hibernate关系映射(一对多)

Posted on 2008-08-21 12:00 H2O 阅读(338) 评论(0)  编辑  收藏 所属分类: hibernate
客户与订单---一对多
package com.yz.pojos;

import java.util.HashSet;
import java.util.Set;

/**
 * Customer generated by MyEclipse Persistence Tools
 */

public class Customer implements java.io.Serializable {

    // Fields

    private Integer cid;

    private String name;

    private String addr;
    //一个客户可以有多个订单，一对多关系。但是一个客户不能有重复的订单，所以用Set集合，set集合不允许出现重复值
    //set集合反映了一个客户的所有订单

    private Set orderses = new HashSet(0);

    // Constructors

    /** default constructor */
    public Customer() {
    }

    /** minimal constructor */
    public Customer(String name) {
        this.name = name;
    }

    /** full constructor */
    public Customer(String name, String addr, Set orderses) {
        this.name = name;
        this.addr = addr;
        this.orderses = orderses;
    }

    // Property accessors

    public Integer getCid() {
        return this.cid;
    }

    public void setCid(Integer cid) {
        this.cid = cid;
    }

    public String getName() {
        return this.name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddr() {
        return this.addr;
    }

    public void setAddr(String addr) {
        this.addr = addr;
    }

    public Set getOrderses() {
        return this.orderses;
    }

    public void setOrderses(Set orderses) {
        this.orderses = orderses;
    }

}
<?xml version="1.0" encoding="utf-8"?>
<!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 Persistence Tools
-->
<hibernate-mapping>
    <class name="com.yz.pojos.Customer" table="customer" lazy="false" >
        <id name="cid" type="java.lang.Integer">
            <column name="cid" />
            <generator class="native" />
        </id>
        <property name="name" type="java.lang.String">
            <column name="name" length="20" not-null="true" />
        </property>
        <property name="addr" type="java.lang.String">
            <column name="addr" length="50" />
        </property>
        <!-- set集合保存该客户所有的订单，通过键cid查找订单 -->
        <set name="orderses"  lazy="true" cascade="delete" inverse="true">
            <key>
                <column name="cid" not-null="true" />
            </key>
            <one-to-many class="com.yz.pojos.Orders" />
        </set>
    </class>
</hibernate-mapping>

订单与客户---多对一
package com.yz.pojos;

import java.util.Date;

/**
 * Orders generated by MyEclipse Persistence Tools
 */

public class Orders implements java.io.Serializable {

    // Fields

    private Integer oid;
    //在多个订单中，每个订单只能属于一个客户，属于 多对一关系，所以要告诉每个订单属于哪一个客户对象
    private Customer customer;

    private Date odate;

    // Constructors

    /** default constructor */
    public Orders() {
    }

    /** full constructor */
    public Orders(Customer customer, Date odate) {
        this.customer = customer;
        this.odate = odate;
    }

    // Property accessors

    public Integer getOid() {
        return this.oid;
    }

    public void setOid(Integer oid) {
        this.oid = oid;
    }

    public Customer getCustomer() {
        return this.customer;
    }

    public void setCustomer(Customer customer) {
        this.customer = customer;
    }

    public Date getOdate() {
        return this.odate;
    }

    public void setOdate(Date odate) {
        this.odate = odate;
    }

}
<?xml version="1.0" encoding="utf-8"?>
<!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 Persistence Tools
-->
<hibernate-mapping>
    <class name="com.yz.pojos.Orders" table="orders" catalog="ssh">
        <id name="oid" type="java.lang.Integer">
            <column name="oid" />
            <generator class="native" />
        </id>
        <!-- 订单与客户多对一，告诉订单所关联的客户是谁 -->
        <many-to-one name="customer" class="com.yz.pojos.Customer" fetch="select">
            <column name="cid" not-null="true" />
        </many-to-one>
        <property name="odate" type="java.util.Date" insert="true">
            <column name="odate" length="19" not-null="true" />
        </property>
    </class>
</hibernate-mapping>

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