MyBatis（三）MyBatis的增删改查

（1）接口中编写方法

     public Emp getEmp(Integer id);

     public void addEmp(Emp emp);

     public void deleteEmp(Integer id);

     public void updateEmp(Emp emp);

（2）编写Mapper文件

 <select id="getEmp" resultType="com.eu.bean.Emp">
     select id,last_name lastName,gender,email from Emp where id = #{id}
   </select>

   <!-- 最后两个属性为获取自增主键的值 如果不需要获取则可以省去 -->
   <insert id="addEmp" parameterType="com.eu.bean.Emp" useGeneratedKeys="true" keyProperty="id">
       INSERT INTO emp(last_name,gender,email)
       VALUES(#{lastName},#{geder},#{email})
   </insert>

   <update id="updateEmp" parameterType="com.eu.bean.Emp">
        update emp
        set last_name = #{lastName},
                gender = #{geder},
                email = #{email}
        where id = #{id}
   </update>

   <delete id="deleteEmp">
       delete from emp where id=#{id}
   </delete>

（3）编写测试

public SqlSessionFactory getSqlSessionFactory() throws IOException {
        String resource = "conf/mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        return new SqlSessionFactoryBuilder().build(inputStream);
    }

    @Test
    public void testMapper() throws IOException {
        SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
        //1.获取到sqlsession 不会自动提交数据
        SqlSession openSession = sqlSessionFactory.openSession();
        EmpDao mapper = openSession.getMapper(EmpDao.class);

        //测试添加

        Emp emp = new Emp(null, "李四", "男","www.com");
        mapper.addEmp(emp);
        System.out.println(emp.getId());
        //测试修改
        /*
         * Emp emp2 = new Emp(3, "李四", "wu", "666333"); mapper.updateEmp(emp2);
         */

        //测试删除
        //mapper.deleteEmp(3);
        //手动提交数据
        openSession.commit();
        openSession.close();
    }