# MyBatis作为一个ORM框架，其重要程度不用过多介绍。下面开始一起学习吧：本博客的编程方法与MyBatis官方文档基本一致：## 1.创建一个数据库mybatis_learn以及对应的表tbl_employee：`CREATE DATABASE mybatis_learn;````CREATE TABLE `tbl_employee` ( `id` int(11) NOT NULL AUTO_INCREMENT, `last_name` varchar(255) DEFAULT NULL, `gender` char(1) DEFAULT NULL, `email` varchar(255) DEFAULT NULL, PRIMARY KEY (`id`)) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;```## 2.创建一个JavaBean(使用了lombok)：```package com.mybatis.learn.bean;import lombok.*;@Getter@Setter@NoArgsConstructor@AllArgsConstructor@ToStringpublic class Employee { private Integer id; private String lastName; private String gender; private String email;}```## 3.正式开始玩Mybatis： ### 3.1 引入依赖或者jar包``` <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>x.x.x</version></dependency>```### 3.2创建SqlSessionFactory（不/使用xml方式）使用xml方式：``` String resource = "mybatis-config.xml"; InputStream inputStream = null; try { inputStream = Resources.getResourceAsStream(resource); } catch (IOException e) { e.printStackTrace(); } SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); ```使用这种方式时，需要你写一个配置文件mybatis-config.xml:```<?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://192.168.1.61:3306/mybatis_learn" /> <property name="username" value="root" /> <property name="password" value="123456" /> </dataSource> </environment> </environments> <!-- 将我们写好的sql映射文件（EmployeeMapper.xml）一定要注册到全局配置文件（mybatis-config.xml）中 --> <mappers> <mapper resource="EmployeeMapper.xml" /> </mappers></configuration>```
当然， 你也可以告别繁琐的xml文件配置：```DataSource dataSource = BlogDataSourceFactory.getBlogDataSource();TransactionFactory transactionFactory = new JdbcTransactionFactory();Environment environment = new Environment("development", transactionFactory, dataSource);Configuration configuration = new Configuration(environment);configuration.addMapper(BlogMapper.class);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(configuration);```
###3.3从 SqlSessionFactory 中获取 SqlSession``` SqlSession session = sqlSessionFactory.openSession(); try { Employee employee = (Employee) session.selectOne("org.mybatis.example.BlogMapper.selectEmployee", 1); System.out.println(employee); } finally { session.close(); }```同时别忘了写具体的sql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.mybatis.example.BlogMapper"> <select id="selectEmployee" resultType="com.mybatis.learn.bean.Employee"> select * from tbl_employee where id = #{id} </select></mapper>```这样子就可以正常查询了(lastName 需要在配置文件中使用别名)
转载于:https://www.cnblogs.com/JackHou/p/10567327.html
相关资源：mybatis_helloworld