Mybatis 入门开发

系统管理员 2022-01-15 03:07 189阅读 0赞

1 创建项目，lib下引入Mybatis的jar包

![20190613202253534.png][]

2 引入数据库连接的jar包

![20190613202351526.png][]

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>
    	
    	<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/mybatis?characterEncoding=utf-8" />
    				<property name="username" value="root" />
    				<property name="password" value="123456" />
    			</dataSource>
    		</environment>
    	</environments>
    	
    	<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">
    
    
    <mapper namespace="test">
    
    
    	
    
    	<select id="findUserById" parameterType="Integer" resultType="com.entity.User">
    		select * from user where id = #{v}
    	</select>
    
    
    	
    
    
    	<select id="findUserByUsername" parameterType="String"
    		resultType="com.entity.User">
                
    		select * from user where username like "%"#{username}"%"
                
    		select * from user where username like '%${value}%'
    	</select>
    
    	
    
    	<insert id="insertUser" parameterType="com.entity.User">
    		
    		<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>
    
    	
    	
    
    	<update id="updateUserByID" parameterType="com.entity.User">
    	update user set username=#{username},sex=#{sex},birthday=#{birthday},address=#{address} where id=#{id}
    	</update>
    
    
    	
    
    	<delete id="deleteUserById" parameterType="Integer">
    	 delete from user where id = #{value}
    	</delete>
    </mapper>

7 加载映射文件

![20190613203335406.png][]

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();
    	}
    		
    }

[20190613202253534.png]: /images/20220115/b2ec3731a2204d8c90d5300f71052cf2.png
[20190613202351526.png]: /images/20220115/0fc70310845140d29fe710f63027db75.png
[20190613203335406.png]: /images/20220115/8628e7d624d5453cbe9228f19b8604b2.png