统计优惠券使用个数, 第一张表是总数,第二张表是已用数量。
select a.coupon_id, a.count, b.used, a.mc_code from (select count(1) as count, c.coupon_id, c.mc_code from T_CS_MEMBER_COUPON_LIST c where c.mc_code = '30862' group by c.coupon_id, c.mc_code) a left join (select count(1) as used, c.coupon_id, c.mc_code from T_CS_MEMBER_COUPON_LIST c where c.mc_code = '30862' and c.use_flag = 1 group by c.coupon_id, c.mc_code) b on a.coupon_id = b.coupon_id
where 要放在left join on 后面
select r.rule_name, c.coupon_id, c.partner_id, c.Mc_Code, c.use_flag, c.actual_discount, c.date_succeed, c.create_on from T_CS_MEMBER_COUPON_LIST c left join t_Cs_Coupon_Rule r on r.id = c.coupon_id where c.mc_code = '30861' and c.coupon_id = 2000