單向N-1關聯(lián)
我新建一個 usersgr實體，再建立一個users將usersgr注入到users里面去
我下面就需要信息注入到映射文件中
<many-to-one name="usersgr" class="com.usersgr" not-found="ignore">
 <column name="typeid" />
</many-to-one>
那如果不加入插入與修改的信息
<many-to-one  name="usersgr" class="com.usersgr"   update="false" insert="false" not-found="ignore">
    <column name="typeid" />
</many-to-one>

雙向的N—N關系 
<set name="usersgr"
table="users"
cascade="all">  
<key column="typeid" not-null="true"/> 
<many-to-many column="addressid"
  class="com.users"/>
</set>
<set name="users"
inverse="true"
table="usersgr"> 
<key column="addressid"/>
<many-to-many column="typeid"
          class="com.usersgr"/>
</set>