MyBatis 增删改查

1. 在 mapper 创建对应的 sql 语句

 <!--namespace 自己命名 -->
<mapper namespace="Usermappar">
    <!--查询-->
    <select id="selectUserById" parameterType="Integer" resultType="bean.User">
    select * from user where id = #{id}
    </select>
   <!--//新增-->
    <insert id="insertUser" parameterType="bean.User">
      insert into user value (#{id},#{name},#{age})
    </insert>

    <!--修改-->
    <update id="updatetUser" parameterType="bean.User">
      update user set name = #{name} where id = #{id}
    </update>

    <!--删除-->
    <delete id="delelctUserById" parameterType="Integer">
      delete from user where id = #{id}
    </delete>
</mapper>

2. 进行操作

公共代码

 //读取配置文件
 String resource = "sqlMapConfig.xml";
 InputStream in= Resources.getResourceAsStream(resource);

 //需要sqlSessionfactoryBulider
 SqlSessionFactoryBuilder builder= new SqlSessionFactoryBuilder();

 //创建需要sqlSessionfactory
 SqlSessionFactory sessionFactory= builder.build(in);

 //生产一个sqlSession
 SqlSession sqlSession=sessionFactory.openSession();

   User user =new User();
   user.setId(6);
   user.setName("baba");
   //新增
   sqlSession.insert("Usermappar.insertUser",user);
   sqlSession.commit();


   //删除
   sqlSession.delete("Usermappar.delelctUserById",6);
   sqlSession.commit();

  User user =new User();
  user.setId(6);
  user.setName("lala");
   //修改
   sqlSession.update("Usermappar.updatetUser",user);
   sqlSession.commit();

   //查询
   User user = sqlSession.selectOne("Usermappar.selectUserById",0);