以下是项目中使用过的频道(channel)与新闻(news)的对应关系，一个channel下可以有多个news,
一个news必须属于某个channel,在增加一个news的时候必须同时增加一个channel_id在news的数据库表字段上，
public class Channel implements Serializable {
 
 /**
  * 
  */
 private static final long serialVersionUID = -5876679362585875098L;
 private int  id;
 private Date create_time;            //  
 private String create_man;           //
 private String title;                //
 private String description;          //
 
private List<News> news;  //一对执有多端的一个集合的引用
 getter();
 setter();
}
 */
public class News implements Serializable {
 /**
  * 
  */
 private static final long serialVersionUID = -6179014966049424520L;
 private int news_id;
 private String title; // 新闻标题
 private String author; // 作者
 private String summary; //
 private String content; //
 private Date create_time;//
 private String source; //
 private int visit_num; //
 private int reply_num;
 private int status;
 private int order_pos;
 private String keywords;
 private Channel channel; //多端执有一端的一个实体引用

  public void setChannelId(int channelId){ 
     this.channel.setId(channelId);
    }
    public int getChannelId(){
     return this.channel.getId();
    }
 // 以上两个方法可以维护它们的映射关系，

 
getter();
setter();

}
ibatis中的channel.xml
<sqlMap namespace="channel">
 <typeAlias alias="channel" type="com.tongdainfo.model.channel.Channel" />
 <typeAlias alias="news" type="com.tongdainfo.model.news.News"/>
 
  
     <resultMap id="channelResult" class="channel"> 
                <result property="id" column="id"/> 
                <result property="create_time" column="create_time"/> 
                <result property="create_man" column="create_man"/> 
                <result property="title" column="title"/> 
                <result property="description" column="description"/> 
                <result property="news" column="id" select="getNewsByChannelId" />
        </resultMap> 
        
    
   
       
 <!-- 添加频道 -->
 <insert id="saveChannel" parameterClass="channel">
 <!-- 
  <selectKey keyProperty="id" resultClass="int">
   <!--[CDATA[
    SELECT LAST_INSERT_ID() AS VALUE
   ]]>
   
  </selectKey>
   -->
  <![CDATA[
   INSERT INTO channel(title,description,create_man,create_time)
   VALUES (#title#,#description#,#create_man#,#create_time#)
  ]]>
 </insert>
</sqlMap>
iBatis 中的news.xml
<sqlMap namespace="news">
 <typeAlias alias="news" type="com.tongdainfo.model.news.News" />
 <typeAlias alias="channel" type="com.tongdainfo.model.channel.Channel" />
 <resultMap id="newsResult" class="news">
  <result property="news_id" column="news_id" />
  <result property="title" column="title" />
  <result property="author" column="author" />
  <result property="summary" column="summary" />
  <result property="create_time" column="create_time" />
  <result property="source" column="source" />
  <result property="visit_num" column="visit_num" />
  <result property="reply_num" column="reply_num" />
  <result property="status" column="status" />
  <result property="order_pos" column="order_pos" />
  <result property="keywords" column="keywords" />
  <result property="channel.id" column="cid" />
  <result property="channel.title" column="ctitle" />
  <result property="channel.description" column="cdescription" />
  <result property="channel.create_man" column="ccreate_man" />
  <result property="channel.create_time" column="ccreate_time" />
 </resultMap>
 <select id="getNewsByChannelId" parameterClass="int" resultMap="newsResult">
  select n.news_id as news_id,n.title as title,n.author as
  author,n.summary as summary,
  n.create_time as create_time,n.source as
  source,n.visit_num as
  visit_num,n.reply_num as reply_num,
  n.keywords as
  keywords,c.id as cid,c.title as ctitle,c.description as
  cdescription,c.creat_man as ccreate_man,
  c.create_time as ccreate_time
  from news AS n
  left join channel as c
  on n.channel_id =c.id
  where
  n.channel_id=#id# 
    </select>
 <!-- 添加新闻 -->
 <insert id="saveNews" parameterClass="news">
  <!--
   <selectKey keyProperty="id" resultClass="int"> <![CDATA[ SELECT
   LAST_INSERT_ID() AS VALUE ]]> </selectKey>
  -->
  <![CDATA[
   INSERT INTO News(title,author,summary,content,create_time,source,visit_num,reply_num,status,order_pos,keywords,channel_id)
   VALUES(#title#,#author#,#summary#,#content#,#create_time#,#source#,#visit_num#,#reply_num#,#status#,#order_pos#,#keywords#,#channelId#)
  
  ]]-->
 </insert>
 <!-- 查询channel下所有新闻列表 -->
 <select id="findNewsByChannelId" parameterClass="int" resultMap="newsResult">
  select n.news_id as news_id,n.title as title,n.author as
  author,n.summary as summary,
  n.create_time as create_time,n.source as
  source,n.visit_num as
  visit_num,n.reply_num as reply_num,
  n.status as
  status,
  n.order_pos as order_pos,
  n.keywords as keywords,
  c.id as
  cid,c.title as ctitle,c.description as
  cdescription,c.create_man as
  ccreate_man,
  c.create_time as ccreate_time
  from news AS n
  left join
  channel as c
  on n.channel_id =c.id
  where n.channel_id=#id# 
    </select>

</sqlMap>