Mybatis系列三：映射文件-增删改查

﹏ヽ暗。殇╰゛Y 2022-04-24 07:56 244阅读 0赞

一、创建EmployeeMapper接口

public interface EmployeeMapper {
    
    	public Employee getEmpById(Integer id);
    
    	public Long addEmp(Employee employee);
    
    	public boolean updateEmp(Employee employee);
    
    	public void deleteEmpById(Integer id);
    	
    }

二、创建EmployeeMapper.xml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="com.atguigu.mybatis.dao.EmployeeMapper">
    
    	
    	<select id="getEmpById" resultType="com.atguigu.mybatis.bean.Employee">
    		select * from tbl_employee where id = #{id}
    	</select>
    
    	
    	
    	
    	
    	<insert id="addEmp" parameterType="com.atguigu.mybatis.bean.Employee"
    			useGeneratedKeys="true" keyProperty="id">
    		insert into tbl_employee(last_name,email,gender) 
    		values(#{lastName},#{email},#{gender})
    	</insert>
    
    	
    	<update id="updateEmp">
    		update tbl_employee 
    		set last_name=#{lastName},email=#{email},gender=#{gender}
    		where id=#{id}
    	</update>
    	
    	
    	<delete id="deleteEmpById">
    		delete from tbl_employee where id=#{id}
    	</delete>
    </mapper>

三、测试增删该查

/**
    	 * 1、mybatis允许增删改直接定义以下类型返回值
    	 * 		Integer、Long、Boolean、void
    	 * 2、我们需要手动提交数据
    	 * 		sqlSessionFactory.openSession();===》手动提交
    	 * 		sqlSessionFactory.openSession(true);===》自动提交
    	 * @throws IOException 
    	 */
    	@Test
    	public void test01() throws IOException{
    		String resource = "mybatis-config.xml";
    		InputStream inputStream = Resources.getResourceAsStream(resource);
    		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    		//1、获取到的SqlSession不会自动提交数据
    		SqlSession openSession = sqlSessionFactory.openSession();
    		try{
    			EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class);
    
    			//查询id为1的员工信息
    			Employee employee = mapper.getEmpById(1);
    			System.out.println(employee);
    
    			//新增员工信息
    			Employee employee1 = new Employee(null, "jerry4",null, "1");
    			mapper.addEmp(employee1);
    			//打印自增主键的值
    			System.out.println(employee1.getId());
    
    			//修改id为1的员工信息
    			Employee employee2 = new Employee(1, "lizq","1820600665@qq.com", "0");
    			boolean updateEmp = mapper.updateEmp(employee2);
    			System.out.println(updateEmp);
    			
    			//删除id为1的员工信息
    			mapper.deleteEmpById(1);
    
    			//2、手动提交数据
    			openSession.commit();
    		}finally{
    			openSession.close();
    		}
    		
    	}