什麽是MyBatis?

MyBatis 是一款優秀的持久層框架，它支持定制化 SQL、存儲過程以及高級映射。MyBatis 避免了幾乎所有的 JDBC 代碼和手動設置參數以及獲取結果集。MyBatis 可以使用簡單的 XML 或註解來配置和映射原生信息，將接口和 Java 的 POJOs(Plain Old Java Objects,普通的 Java對象)映射成數據庫中的記錄。

MyBatis源碼對應的結構流程

1. SqlMapConfig.xml，此文件作為mybatis的全局配置文件，配置了mybatis的運行環境等信息。mapper.xml文件即sql映射文件，文件中配置了操作數據庫的sql語句，此文件需要在SqlMapConfig.xml中加載。

<?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>  
  <environments default="development">  
    <environment id="development">  
      <transactionManager type="JDBC" />  
      <dataSource type="POOLED">  
     <property name="driver" value="com.mysql.jdbc.Driver" />    
         <property name="url" value="jdbc:mysql://localhost:3306/seckill?useUnicode=true&characterEncoding=utf-8" />    
         <property name="username" value="root" />    
         <property name="password" value="mysql123" />  
      </dataSource>  
    </environment>  
  </environments>  
    <mappers>  
       <mapper  resource="com/louis/mybatis/domain/EmployeesMapper.xml"/>  
    </mappers>  
</configuration>

mapper.xml

<?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="com.louis.mybatis.dao.EmployeesMapper" >  
  
  <resultMap id="BaseResultMap" type="com.louis.mybatis.model.Employee" >  
    <id column="EMPLOYEE_ID" property="employeeId" jdbcType="DECIMAL" />  
    <result column="FIRST_NAME" property="firstName" jdbcType="VARCHAR" />  
    <result column="LAST_NAME" property="lastName" jdbcType="VARCHAR" />  
    <result column="EMAIL" property="email" jdbcType="VARCHAR" />  
    <result column="SALARY" property="salary" jdbcType="DECIMAL" />  
  </resultMap>  
    
  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >  
    select   
        EMPLOYEE_ID, FIRST_NAME, LAST_NAME, EMAIL, SALARY  
        from LOUIS.EMPLOYEES  
        where EMPLOYEE_ID = #{employeeId,jdbcType=DECIMAL}  
  </select>  
</mapper>

本文出自 “數據挖掘工程師的成長歷程” 博客，請務必保留此出處http://qianqiansun.blog.51cto.com/13271301/1965203

MyBaits基本概念和原理