MyBatis实现数据库的CRUD

今天药忘吃喽~ 2022-06-16 13:47 234阅读 0赞

首先是数据库的映射文件:

<mapper namespace="com.test.dao.EmployeeMapper">
    	
    	<select id="getEmpById" resultType="com.test.beans.Employee">
    		SELECT id,last_name lastName,email,gender from tb1_emplyee where id = #{id}
    	</select>
    	
    	<insert id="addEmp" parameterType="com.test.beans.Employee"
    	  useGeneratedKeys="true" keyProperty="id">
    		INSERT  INTO tb1_emplyee(last_name,email,gender)VALUES (#{lastName},#{email},#{gender})
    	</insert>
    	
    	<update id="updateEmp">
    		UPDATE tb1_emplyee SET last_name=#{lastName},email=#{email},gender=#{gender} WHERE  id=#{id}
    	</update>
    	
    	<delete id="deleteEmpById">
    		DELETE FROM tb1_emplyee WHERE  id=#{id}
    	</delete>
    </mapper>

注册到全局配置文件中:

测试代码:

@Test
    public void test03() throws IOException{
    		SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
    		//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);
    			//测试添加
    			/*Employee employee = new Employee(null,"superman","24238788@qq.com", "1");
    			mapper.addEmp(employee);
    			System.out.println(employee.getId());*/
    			//测试修改
    			/*Employee employee = new Employee(1, "Tom", "jerry@123.com", "0");
    			boolean updateEmp = mapper.updateEmp(employee);
    			System.out.println(updateEmp);*/
    			//测试删除
    			mapper.deleteEmpById(2);
    			//2、手动提交数据
    			openSession.commit();
    		}
                    finally{
    			openSession.close();
    		}

这里数据库中设置了主键自增长,如果需要获取主键的值,需要在配置文件中做如下的配置:

useGeneratedKeys="true" keyProperty="id"

不然是获取不了id的。