Hibernate 多对多映射实列 (复合主键)

               <id name="id" type="integer">
			<column name="userId" />
			<generator class="sequence">
				<param name="sequence">SEQ_IRCS_USER_ID</param>
			</generator>
	</id>
..................
       <set name="ircsGroups" table="TB_IRCS_USERGROUP" lazy="true" inverse="false"  cascade="save-update" batch-size="5"  sort="unsorted" >
            <key column="userId"/>
            <many-to-many class="net.p5w.common.po.ircs.IrcsGroup">
            <column name="groupCode"  not-null="true"  length="12"></column>
            <column name="stockcode"  not-null="true"   length="8" ></column>
            <column name="stocktype"  not-null="true"  length="1" ></column>
            </many-to-many>
        </set>

 以上为：IrcsUser.hbm.xml

 

 

 

 

	<composite-id>
			<key-property name="groupCode" type="string">
				<column name="groupCode" length="12" />
			</key-property>		
			<key-property name="stockCode" type="string">
				<column name="stockcode" length="8" />
			</key-property>
			<key-property name="stockType" type="string">
				<column name="stocktype" length="1" />
			</key-property>
	</composite-id>



<set name="ircsUsers" table="TB_IRCS_USERGROUP" lazy="true" inverse="false"  cascade="save-update" batch-size="5" sort="unsorted">
            <key>
            <column name="stockcode"  not-null="true"  length="8" ></column>
            <column name="stocktype"  not-null="true"  length="1" ></column>
            <column name="groupCode"  not-null="true"  length="12"></column>
            </key>
            <many-to-many class="net.p5w.common.po.ircs.IrcsUser" column="userId"/>
        </set> 

 以上为：IrcsGroup.hbm.xml

 

注意：set中的key 的顺序与实体类的属性顺序一致！！！！

 

 

评论

2 楼 txy821 2010-03-19  

Hibernate 3.0.5

1、Usergroup.hbm.xml 用户组表
         <set name="users" table="Groupandusers" lazy="true" inverse="false" cascade="save-update" sort="unsorted">
            <key column="GROUPID"/>
            <many-to-many class="cn.com.commnet.model.systems.Users" column="USERID" outer-join="auto"/>
        </set>


2、Users.hbm.xml 用户表
        <set name="groups" table="Groupandusers" lazy="true" inverse="false" cascade="save-update" sort="unsorted" >
            <key column="USERID"/>
            <many-to-many class="cn.com.commnet.model.systems.Usergroup" column="GROUPID" outer-join="auto"/>
        </set>

3、Model  Usergroup.java
private Set users = new HashSet();
public Set getUsers() {
        return users;
    }

    public void setUsers(Set users) {
        this.users = users;
    }
   
    public void addUser(RgUsers user) {
        users.add(user);
    }
   
    public void updateUsers(Set newUserset){
        //get intersection elements 取交集
        this.getUsers().retainAll(newUserset);
        //get the refresh set in new set 新的集合中取补集
        newUserset.removeAll( this.getUsers());
        //get the refreshed data 最终的集合
        this.getUsers().addAll(newUserset);
    }

4、Model    Users.java
private Set groups = new HashSet();

    public Set getGroups() {
        return groups;
    }

    public void setGroups(Set groups) {
        this.groups = groups;
    }
   
    public void addGroup(RgUsergroup group) {
        groups.add(group);
    }
   
    public void updateGroups(Set newGroupset){
        //get intersection elements 取交集
        this.getGroups().retainAll(newGroupset);
        //get the refresh set in new set 新的集合中取补集
        newGroupset.removeAll( this.getGroups());
        //get the refreshed data 最终的集合
        this.getGroups().addAll(newGroupset);
    //父接点一侧的配置应为 cascade="all-delete-orphan" ，
    //否则子接点只能修改和新增，集合中删除掉的子接点，在数据库中并没有被删除掉。
    }

5、Service 层  UserManager.java
            a). add 方法:
            String[] groupList = form.getGroupList();
             for(int i=0;i<groupList.length;i++) {
                 RgUsergroup group = new UserGroupDAO().getGroupById(Long.valueOf(groupList[i]),false);
                 user.addGroup(group);
             }
            dao.save(user);
           b). update 方法:
            Set newGroupset = new HashSet();
             String[] groupList = form.getGroupList();
             for(int i=0;i<groupList.length;i++) {
                 RgUsergroup group = new UserGroupDAO().getGroupById(Long.valueOf(groupList[i]),false);
                 newGroupset.add(group);
             }
             user.updateGroups(newGroupset);   //更新多对多对应表
            dao.update(user);

    另外， 多对多， 及一对多的关联查询时， 通过外键属性的条件进行查询， 如:
    String strSql = "from Users t where t.groups.groupid =?"

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1 楼 txy821 2010-03-19  

IrcsUser.hbm.xml 正确定法：

        <set name="ircsGroups" table="TB_IRCS_USERGROUP" lazy="false" inverse="false" cascade="save-update"  batch-size="5"  sort="unsorted" >
            <key column="userId"/>
            <many-to-many class="net.p5w.common.po.ircs.IrcsGroup"  outer-join="auto">
            <column name="groupCode"  not-null="true"  length="12"></column>
            <column name="stockcode"  not-null="true"   length="8" ></column>
            <column name="stocktype"  not-null="true"  length="1" ></column>
            </many-to-many>
        </set>

IrcsGroup.hbm.xml正确写法:

        <set name="ircsUsers" table="TB_IRCS_USERGROUP" lazy="false" inverse="false"  cascade="save-update" batch-size="5" sort="unsorted">
            <key>
            <column name="groupCode"  not-null="true"   length="12"></column>
            <column name="stockcode"  not-null="true"   length="8" ></column>
            <column name="stocktype"  not-null="true"  length="1" ></column>
            </key>
            <many-to-many class="net.p5w.common.po.ircs.IrcsUser"   outer-join="auto" column="userId"/>
        </set>

cascade="save-update" 改成 cascade="all-delete-orphan" 要慎用。。它不仅会删除中间表，还会把对关联的表记录也会删除。
当只要求删除中间表时，只需要加outer-join="auto"