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