mysql 拼接

SELECT GROUP_CONCAT(CAST(coupon_amount as SIGNED) separator ',')
FROM ellabook_coupon WHERE coupon_subject_id=#{couponSubjectId,jdbcType=VARCHAR}
AND member_id=(SELECT member_id FROM ellabook_coupon
WHERE coupon_subject_id=#{couponSubjectId,jdbcType=VARCHAR} GROUP BY member_id LIMIT 0,1)