这一章节是本系列文章最后一篇。经历过前三篇文章的洗礼,相信你对 iBATIS SQL Maps 有比较详细的认识了吧? 
  
来看看新需求: 
张三后来做生意,自己经营得很好,打算再买辆车跑运输。对于第二次买车,车辆管理系统的 PEOPLE 表原本已经记录了他的基本信息,遂不对 PEOPLE 表操作。只向 AUTO_INFO表 insert 一条车辆记录即可。 
  
新需求所用到的技术要点都在《iBATIS SQL Maps(二)》和《iBATIS SQL Maps(三)》中出现过了。请看映射文件: 
  
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 <?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE sqlMap     PUBLIC "-//iBATIS.com//DTD SQL Map 2.0//EN"     "http://www.ibatis.com/dtd/sql-map-2.dtd"> 
<sqlMap> 
  <insert id="insertAutoInfo" parameterClass="bo.AutoInfo">     <![CDATA[        insert into auto_info (license_plate, owner_no) values (#licensePlate#, #ownerNo.id#)     ]]>   </insert> 
    <resultMap id="get-autoInfo-result" class="bo.AutoInfo">         <result property="id" column="auto_id"/>         <result property="licensePlate" column="license_plate"/>     </resultMap> 
    <resultMap id="get-people-result" class="bo.People">         <result property="id" column="owner_id"/>         <result property="name" column="name"/>         <result property="address" column="address"/>         <result property="autoInfoList" column="owner_id" select="getAutoInfo"/>     </resultMap> 
  <select id="getPeople" resultMap="get-people-result" parameterClass="bo.People">        <![CDATA[         select * from people        ]]>        <dynamic prepend="where">          <isNotNull property="id">            <![CDATA[             owner_id=#id#            ]]>          </isNotNull>        </dynamic>   </select> 
  <select id="getAutoInfo" resultMap="get-autoInfo-result" parameterClass="int">        <![CDATA[         select * from auto_info where owner_no=#id#         ]]>   </select>    </sqlMap>  |     
简单地组合一下以前出现过的映射文件,就能满足新需求。相应程序代码如下: 
  
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 package test; 
import java.io.Reader; 
import com.ibatis.sqlmap.client.*; import com.ibatis.common.resources.*; 
import bo.*; 
public class AutoMag { 
 private Reader reader;  private SqlMapClient sqlMap;  private String resource = "SqlMapConfig.xml";    public void insertPeople() throws Exception{   try{        reader = Resources.getResourceAsReader(resource);        sqlMap=SqlMapClientBuilder.buildSqlMapClient(reader);        sqlMap.startTransaction();               People people=new People();        people.setId(new Integer("1"));        people=(People)sqlMap.queryForObject("getPeople",people); 
       AutoInfo autoInfo=new AutoInfo();        autoInfo.setLicensePlate("A00002");        autoInfo.setOwnerNo(people);        sqlMap.insert("insertAutoInfo",autoInfo);               sqlMap.commitTransaction();   }finally{        sqlMap.endTransaction();   }  } }  |     
程序代码也是简单组合一下而已,想想 Hibernate 又是怎么写的呢?相信有 JDBC 经验的程序员应该更喜欢 iBATIS SQL Maps ! 
  
斗转星移、峰回路转,张三在经历过生意红火之后,接下来的一年内生意场上连连告负,不得不把自己的摊子收缩一下。这第一件事要把跑运输的车卖掉,就是那辆牌照为“A00002”的。 
  
相应映射文件只需小小修改: 
  
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 <?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE sqlMap     PUBLIC "-//iBATIS.com//DTD SQL Map 2.0//EN"     "http://www.ibatis.com/dtd/sql-map-2.dtd"> 
<sqlMap>      <delete id="deleteAutoInfo" parameterClass="bo.AutoInfo">     <![CDATA[      delete from auto_info where license_plate=#licensePlate# and owner_no=#ownerNo.id#     ]]>   </delete> 
    <resultMap id="get-autoInfo-result" class="bo.AutoInfo">         <result property="id" column="auto_id"/>         <result property="licensePlate" column="license_plate"/>     </resultMap> 
    <resultMap id="get-people-result" class="bo.People">         <result property="id" column="owner_id"/>         <result property="name" column="name"/>         <result property="address" column="address"/>         <result property="autoInfoList" column="owner_id" select="getAutoInfo"/>     </resultMap> 
  <select id="getPeople" resultMap="get-people-result" parameterClass="bo.People">        <![CDATA[         select * from people        ]]>        <dynamic prepend="where">          <isNotNull property="id">            <![CDATA[             owner_id=#id#            ]]>          </isNotNull>        </dynamic>   </select> 
  <select id="getAutoInfo" resultMap="get-autoInfo-result" parameterClass="int">        <![CDATA[         select * from auto_info where owner_no=#id#         ]]>   </select>    </sqlMap>  |     
添加了一个 delete 类型的 Mapped Statement。同样,也无需再解释了。相应程序代码: 
  
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 package test; 
import java.io.Reader; 
import com.ibatis.sqlmap.client.*; import com.ibatis.common.resources.*; 
import bo.*; 
public class AutoMag { 
 private Reader reader;  private SqlMapClient sqlMap;  private String resource = "SqlMapConfig.xml";    public void delPeople() throws Exception{   try{       reader = Resources.getResourceAsReader(resource);       sqlMap=SqlMapClientBuilder.buildSqlMapClient(reader);       sqlMap.startTransaction();              People people=new People();       people.setId(new Integer("1"));       people=(People)sqlMap.queryForObject("getPeople",people); 
        AutoInfo autoInfo=new AutoInfo();         autoInfo.setLicensePlate("A00002");         autoInfo.setOwnerNo(people);                   sqlMap.delete("deleteAutoInfo",autoInfo);              sqlMap.commitTransaction();   }finally{       sqlMap.endTransaction();   }  } }  |     
到这里,iBATIS SQL Maps 之旅也就结束了。是的,很有意犹未尽的感觉,还没按照 one-to-many 方式删除张三和他所有的车辆呢。 
这个工作就留给你来完成吧! 
  
    我不想比较 Hibernate 和 iBATIS SQL Maps 孰优孰劣,因为这种比较实在无聊!从我开始写第一行 Delphi 代码开始,就充斥着“VC 好?还是 Delphi 好?”这样的比较!如果你尚未涉足过 JDBC,我想Hibernate 会更适合你… …
 
  (请注意!引用、转贴本文应注明原作者:Rosen Jiang 以及出处:http://blog.csdn.net/rosen)  
 
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