resultType和resultMap只能有一個(gè)成立，resultType是直接表示返回類型的，而resultMap則是對(duì)外部ResultMap的引用，resultMap解決復(fù)雜查詢是的映射問題。比如：列名和對(duì)象屬性名不一致時(shí)可以使用resultMap來配置；還有查詢的對(duì)象中包含其他的對(duì)象等。
MyBatisConfig.xml
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<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration><!--定義別名 注意typeAliases一定要在environments之前--><typeAliases><typeAlias type="jike.book.pojo.JiKeUser" alias="JiKeUser"/></typeAliases><environments default="development"><environment id="development"><transactionManager type="JDBC"></transactionManager><dataSource type="POOLED"><property name="driver" value="com.mysql.jdbc.Driver"/><property name="url" value="jdbc:mysql://localhost:3306/jikebook"/><property name="username" value="root"/><property name="password" value="*****"/></dataSource></environment></environments><mappers><mapper resource="jike/book/map/jikeUser.xml"/><mapper class="jike.book.Impl.InterfaceJikeUserMap"/></mappers></configuration> |
jikeUser.xml
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<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="/"><resultMap id="JiKeUserMap" type="JiKeUser"><id property="id" column="id"/><result property="userName" column="userName"/><result property="password" column="password"/></resultMap><select id="selectUserMap" resultMap="JiKeUserMap">select * from jikeUser;</select><select id="selectUserList" resultType="JiKeUser" parameterType="JiKeUser">select * from jikebook.jikeuser;</select></mapper> |
TestSelect.java
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package jike.book.test;import jike.book.pojo.JiKeUser;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;import java.io.IOException;import java.io.Reader;import java.util.List;/*** DateTime: 2016/9/5 21:45* 功能：* 思路：*/public class TestSelect {public static void main(String[] args) {// 資源路徑String resource="jike/book/map/MyBatisConfig.xml";Reader reader=null;SqlSession session;try {reader= Resources.getResourceAsReader(resource);} catch ( IOException e ) {e.printStackTrace();}SqlSessionFactory sqlMapper=new SqlSessionFactoryBuilder().build(reader);session=sqlMapper.openSession();List<JiKeUser> list=session.selectList("selectUserMap");// List<JiKeUser> list=session.selectList("selectUserList");for(JiKeUser jiKeUser:list){System.out.println(jiKeUser.getUserName());}session.close();}} |
運(yùn)行
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List<JiKeUser> list=session.selectList("selectUserMap"); |
或者
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List<JiKeUser> list=session.selectList("selectUserList"); |
結(jié)果都是一樣的
以上所述是小編給大家介紹的Mybatis中的resultType和resultMap查詢操作實(shí)例詳解，希望對(duì)大家有所幫助，如果大家有任何疑問請(qǐng)給我留言，小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)服務(wù)器之家網(wǎng)站的支持！
原文鏈接：http://blog.csdn.net/yen_csdn/article/details/52444207
