hibernate多对一的映射的配置

public class Group {
 
 private int id;
 private String groupName;

｝

 

public class User {
 private int id;
 private String username;
 private String userpwd;
 private Group group;
 ｝

 

 

 

<class name="Group" table="t_group">
        <id name="id" >
            <column name="id" />
            <generator class="native"></generator>
        </id>
        <property name="groupName" >
            <column name="groupName" length="50" />
        </property>
    </class>

 

<class name="User"  >
        <id name="id" >
            <column name="id" />
            <generator class="native"></generator>
        </id>
        <property name="username" >
            <column name="username" length="50" />
        </property>
        <property name="userpwd" >
            <column name="userpwd" length="50" />
        </property>
       
        <many-to-one name="group" column="t_group"></many-to-one>