wechatbak/wjj-core/target/classes/mybatis/NumMapper.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="com.demo.wjj.mapper.NumMapper">

    <update id="update">
        UPDATE tb_num SET step=#{step} WHERE id = #{id}
    </update>

    <select id="findObjectById" resultType="com.demo.wjj.po.TbNum">
        SELECT id,size,step FROM tb_num WHERE id = #{id}
    </select>
</mapper>