簡述 多對多關系映射

多對多關系映射需要一張中間表來維護關系

　　一：Role類與Function類

1 public class Function {
2     private int id;
3     private String name;
4     private String code;
5     private String url;
6     private Set<Role> roles = new HashSet<Role>();
7     
8     set/get....
9 }

1 public class Role {
2     private int id;
3     private String name;
4     private Set<Function> functions = new HashSet<Function>();
5     
6         set/get.....
7 }

　　二：配置hbm.xml

<hibernate-mapping package="cn.pojo">
    <class name="Role">
        <id name="id">
            <generator class
 
="native"></generator>
        </id>
        
        <property name="name"></property>
        
        <!-- 多對多 -->
        <set name="functions" table="rol_func">
            <!-- 表示當前類映射到關系表中的列 -->
            <key column="rid"></key>
            <!-- 表示所對應的另一方在關系表中的列 -->
            <many-to-many column="fid" class
 
="Function"></many-to-many>
        </set>
    </class>
</hibernate-mapping>

雙向多對多映射同理配置hbm.xml

Hibernate學習之路（五）