jiangchengfeiyi-houduan/src/main/resources/mapper/CouponMapper.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.cultural.heritage.mapper.CouponMapper">
        <select id="verifyIsReachTheUpperLimit" resultType="Integer">
            select sum(quantity) from exchange_record where userId = #{userId} and couponId = #{couponId}
        </select>
</mapper>