MyBatis 基本演示

主配置文件

 <?xml version="1.0" encoding="UTF-8" ?>

 <!DOCTYPE configuration
     PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
     "http://mybatis.org/dtd/mybatis-3-config.dtd">

 <configuration>

   <settings>
     <setting name="useGeneratedKeys" value="false"/>
     <setting name="useColumnLabel" value="true"/>
   </settings>

   <typeAliases>
     <typeAlias alias="UserAlias" type="org.apache.ibatis.submitted.complex_property.User"/>
   </typeAliases> -
   <environments default="development">
     <environment id="development">
       <transactionManager type="JDBC">
         <property name="" value=""/>
       </transactionManager>
       <dataSource type="UNPOOLED">
         <property name="driver" value="com.mysql.jdbc.Driver"/>
         <property name="url" value="jdbc:mysql://127.0.0.1:3306/micro_message"/>
         <property name="username" value="root"/>
         <property name="password" value="root"/>
       </dataSource>
     </environment>
   </environments>

   <mappers>
     <mapper resource="com/imooc/config/sqlxml/Message.xml"/>
   </mappers>

 </configuration>

映射文件

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE mapper
     PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
     "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

 <mapper namespace="org.zln.domain.Message">

     <resultMap id="messageResult" type="message">
         <id property="id" column="ID" jdbcType="INTEGER"/>
         <result property="command" column="COMMAND" jdbcType="VARCHAR"/>
         <result property="description" column="DESCRIPTION" jdbcType="VARCHAR"/>
         <result property="content" column="CONTENT" jdbcType="VARCHAR"/>
     </resultMap>

     <select id="queryMessageList" resultMap="messageResult">
         SELECT id,command,description,content FROM message
     </select>
 </mapper>

初始化配置文件

 package com.imooc.db;

 import java.io.IOException;
 import java.io.Reader;

 import org.apache.ibatis.io.Resources;
 import org.apache.ibatis.session.SqlSession;
 import org.apache.ibatis.session.SqlSessionFactory;
 import org.apache.ibatis.session.SqlSessionFactoryBuilder;

 /**
  * 访问数据库类
  */
 public class DBAccess {
     public SqlSession getSqlSession() throws IOException {
         // 通过配置文件获取数据库连接信息
         Reader reader = Resources.getResourceAsReader("com/imooc/config/Configuration.xml");
         // 通过配置信息构建一个SqlSessionFactory
         SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
         // 通过sqlSessionFactory打开一个数据库会话
         SqlSession sqlSession = sqlSessionFactory.openSession();
         return sqlSession;
     }
 }

Dao

 package org.zln.dao;

 import org.springframework.stereotype.Repository;
 import org.zln.domain.Message;

 import java.util.List;

 /**
  * Created by sherry on 000006/7/6 19:16.
  */
 @Repository
 public class MessageDao extends BaseDao {

     public List<Message> queryMessageList(String command,String description){
         return sqlSessionTemplate.selectList("org.zln.domain.Message.queryMessageList");
     }
 }

在MyBatis中，必须使用命名空间，不是在调用sql的时候，没有书写命名空间也能找到对应的id