Mybatis 入门开发

1 创建项目，lib下引入Mybatis的jar包

 2 引入数据库连接的jar包

3 选中所有lib下的包右键Build Path

 4 编写Mybatis核心配置文件（sqlMapConfig.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>
	<!-- 和spring整合后 environments配置将废除 -->
	<environments default="development">
		<environment id="development">
			<!-- 使用jdbc事务管理 -->
			<transactionManager type="JDBC" />
			<!-- 数据库连接池 -->
			<dataSource type="POOLED">
				<property name="driver" value="com.mysql.jdbc.Driver" />
				<property name="url"
					value="jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8" />
				<property name="username" value="root" />
				<property name="password" value="123456" />
			</dataSource>
		</environment>
	</environments>
	<!-- mapper的位置 -->
	<mappers>
	<mapper resource="sqlmap/User.xml"/>
	</mappers>
</configuration>

 5 创建POJO类

public class User{
	private Integer id;
	private String username;
	private String sex;
	private Date birthday;
	private String address;
    .......get/set方法........

}

6 创建sql映射User.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">
<!-- sql语句 -->
<!-- namespace:命名空间 -->
<mapper namespace="test">


	<!-- 通过id查询一个用户 -->

	<select id="findUserById" parameterType="Integer" resultType="com.entity.User">
		select * from user where id = #{v}
	</select>


	<!--              根据用户名称模糊查询用户列表
	 #{} 占位符(带引号) 		  select * from user where id = ? ？ ==  '欧文' 
	 ${} 字符拼接('%赵薇%')    select * from user where username like '%${}%' -->


	<select id="findUserByUsername" parameterType="String"
		resultType="com.entity.User">
            <!-- 防sql注入 -->
		select * from user where username like "%"#{username}"%"
            <!-- 如果传入的参数是简单数据类型，${}里面必须写value -->
		select * from user where username like '%${value}%'
	</select>

	<!-- 添加用户 -->

	<insert id="insertUser" parameterType="com.entity.User">
		<!-- 添加用户后用户下单，需要返回用户的id 使用selectKey -->
		<selectKey keyProperty="id" resultType="Integer" order="AFTER">
			select LAST_INSERT_ID()
		</selectKey>
		insert into user(username,sex,birthday,address)
		values(#{username},#{sex},#{birthday},#{address})
	</insert>

	
	<!-- 修改 -->

	<update id="updateUserByID" parameterType="com.entity.User">
	update user set username=#{username},sex=#{sex},birthday=#{birthday},address=#{address} where id=#{id}
	</update>


	<!-- 删除 -->

	<delete id="deleteUserById" parameterType="Integer">
	 delete from user where id = #{value}
	</delete>
</mapper>

7 加载映射文件

 

8 编写测试类进行测试验证

package com.junit;

import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.List;

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

import com.entity.User;

public class MybatisCURDTest {
	//根据用户id查询一个用户
	@Test
	public void testfindUserById() throws IOException {
		//加载核心配置文件
		String resource = "sqlMapConfig.xml";
		InputStream in = Resources.getResourceAsStream(resource);
		// 创建SqlSessionFactory
		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
		//创建SqlSession
		SqlSession sqlSession = sqlSessionFactory.openSession();
		//执行sql语句
		User user = sqlSession.selectOne("test.findUserById", 10);
	}
	//根据用户名称模糊查询用户列表
		@Test
		public void testfindUserByUsername() throws IOException {
			//加载核心配置文件
			String resource = "sqlMapConfig.xml";
			InputStream in = Resources.getResourceAsStream(resource);
			// 创建SqlSessionFactory
			SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
			//创建SqlSession
			SqlSession sqlSession = sqlSessionFactory.openSession();
			//执行sql语句
			List<User> users = sqlSession.selectList("test.findUserByUsername", "陈小明");
			for (User user : users) {
				System.out.println(user);
			}
		}
		
		//添加用户
		@Test
		public void testInsertUser() throws IOException {
			//加载核心配置文件
			String resource = "sqlMapConfig.xml";
			InputStream in = Resources.getResourceAsStream(resource);
			// 创建SqlSessionFactory
			SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
			//创建SqlSession
			SqlSession sqlSession = sqlSessionFactory.openSession();
			//执行sql语句
			User user = new User();
			user.setUsername("陈安安");
			user.setBirthday(new Date());
			user.setAddress("杭州");
			user.setSex("女");
			int i = sqlSession.insert("test.insertUser", user);
			//提交
			sqlSession.commit();
			System.out.println(user.getId());
		}

	// 修改用户
	@Test
	public void testUpdateUser() throws IOException {
		// 加载核心配置文件
		String resource = "sqlMapConfig.xml";
		InputStream in = Resources.getResourceAsStream(resource);
		// 创建SqlSessionFactory
		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
		// 创建SqlSession
		SqlSession sqlSession = sqlSessionFactory.openSession();
		// 执行sql语句
		User user = new User();
		user.setId(28);
		user.setUsername("小黑");
		user.setBirthday(new Date());
		user.setAddress("杭州22");
		user.setSex("女");
		int i = sqlSession.update("test.updateUserByID", user);
		// 提交
		sqlSession.commit();
	}
	// 删除用户
	@Test
	public void testdeleteUser() throws IOException {
		// 加载核心配置文件
		String resource = "sqlMapConfig.xml";
		InputStream in = Resources.getResourceAsStream(resource);
		// 创建SqlSessionFactory
		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
		// 创建SqlSession
		SqlSession sqlSession = sqlSessionFactory.openSession();
		// 执行sql语句
		sqlSession.delete("test.deleteUserById", 29);
		// 提交
		sqlSession.commit();
	}
		
}