Mybatis增删改查。Mybatis入门操作

不念不忘少年蓝@ 2022-05-18 09:09 372阅读 0赞

# 目的： 使用Mybatis完成增删改查功能。 #

### 第一步，配置好mybatis的环境，参考博客： ###

[https://blog.csdn.net/tomwildboar/article/details/81329060][https_blog.csdn.net_tomwildboar_article_details_81329060]

### 第二步：pojo，和sqlMapConfig.xml主配置文件和上面博客中一样，就不写了。直接给出test和User.xml文件 ###

User.xml配置文件

<?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="test">
    	
    	
    	<select id="findUserById" parameterType="Integer" resultType="com.ziyang.mybatis.pojo.User">
    		select * from user where id = #{a}
    	</select>
    	
    	<select id="findUserByUsername" parameterType="String" resultType="com.ziyang.mybatis.pojo.User">
    		
    		select * from user where username like "%"#{value}"%"
    	
    	</select> 
    	
    	
    	<insert id="insertUser" parameterType="com.ziyang.mybatis.pojo.User">
    		
    		<selectKey keyProperty="id" resultType="Integer" order="AFTER">
    			select LAST_INSERT_ID()
    		</selectKey>
    		insert into user (username,birthday,sex,address) 
    		values (#{username},#{birthday},#{sex},#{address}) 
    	</insert>
    	
    	
    	<update id="updateUserById" parameterType="com.ziyang.mybatis.pojo.User">
    		update user
    		set username = #{username},sex = #{sex},
    			birthday = #{birthday},address = #{address}
    		where id = #{id}
    	
    	</update>
    	
    	
    	<delete id="deleteById" parameterType="Integer">
    		delete from user 
    		where id = #{v} 
    	</delete>	
    	
    	
    </mapper>

test测试类

package com.ziyang.mybatis.test;
    
    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.SqlSession;
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.apache.ibatis.session.SqlSessionFactoryBuilder;
    import org.junit.Test;
    
    import com.ziyang.mybatis.pojo.User;
    
    public class Demo_1 {
    	
    	/*根据id查询*/
    //	@Test
    //	public void test1() throws IOException {
    //		//加载核心配置文件
    //		InputStream stream = Resources.getResourceAsStream("sqlMapConfig.xml");
    //		//创建一个sqlSessionFactory
    //		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(stream);
    //		//创建sqlsession
    //		SqlSession sqlSession = sqlSessionFactory.openSession();
    //		//执行sql语句
    //		User user = sqlSession.selectOne("test.findUserById",1);
    //		
    //		System.out.println(user);
    //	}
    	
    	/*根据name模糊查询*/
    	@Test
    	public void test2() throws IOException {
    		//加载核心配置文件
    		InputStream stream = Resources.getResourceAsStream("sqlMapConfig.xml");
    		//创建一个sqlSessionFactory
    		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(stream);
    		//创建sqlsession
    		SqlSession sqlSession = sqlSessionFactory.openSession();
    		//执行sql语句
    		List<User> user = sqlSession.selectList("test.findUserByUsername","五");
    		for (User user2 : user) {
    			System.out.println(user2);
    		}
    		
    	}
    	/*添加用户*/
    	@Test
    	public void test3() throws IOException {
    		//加载核心配置文件
    		InputStream stream = Resources.getResourceAsStream("sqlMapConfig.xml");
    		//创建一个sqlSessionFactory
    		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(stream);
    		//创建sqlsession
    		SqlSession sqlSession = sqlSessionFactory.openSession();
    		//执行sql语句
    		User user = new User();
    		user.setUsername("aa");
    		user.setBirthday(new Date());
    		user.setAddress("aaa");
    		user.setSex("a");
    		int i = sqlSession.insert("test.insertUser",user);
    		sqlSession.commit();
    		System.out.println(user.getId());
    		
    	}
    	
    	/*添加用户*/
    	@Test
    	public void test4() throws IOException {
    		//加载核心配置文件
    		InputStream stream = Resources.getResourceAsStream("sqlMapConfig.xml");
    		//创建一个sqlSessionFactory
    		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(stream);
    		//创建sqlsession
    		SqlSession sqlSession = sqlSessionFactory.openSession();
    		//执行sql语句
    		User user = new User();
    		user.setId(27);
    		user.setUsername("bb");
    		user.setBirthday(new Date());
    		user.setAddress("bb");
    		user.setSex("b");
    		int i = sqlSession.update("test.updateUserById", user);
    		sqlSession.commit();
    		
    	}
    	
    	//删除	
    	@Test
    	public void test5() throws IOException {
    		//加载核心配置文件
    		InputStream stream = Resources.getResourceAsStream("sqlMapConfig.xml");
    		//创建一个sqlSessionFactory
    		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(stream);
    		//创建sqlsession
    		SqlSession sqlSession = sqlSessionFactory.openSession();
    		//执行sql语句
    		
    		int i = sqlSession.delete("test.deleteById", 27);
    		sqlSession.commit();
    		
    	}
    	
    	
    	
    }

[https_blog.csdn.net_tomwildboar_article_details_81329060]: https://blog.csdn.net/tomwildboar/article/details/81329060