Question

如何选择所有超过3个并发优惠的客户？

我有的优惠表有这些专栏：

custid offerid  inidate        enddate        title
    12,     33, "2016-01-15" , "2016-01-30" , "offer 33" 
    12,     34, "2016-01-18" , "2016-01-22" , "offer 34" 
    12,     35, "2016-01-20" , "2016-01-30" , "offer 35"
    12,     36, "2016-02-01" , "2016-02-30" , "offer 36"
   106,     43, "2016-01-15" , "2016-01-30" , "offer 43" 
   106,     44, "2016-01-18" , "2016-01-22" , "offer 44" 
   106,     45, "2016-01-20" , "2016-01-30" , "offer 45"
   106,     46, "2016-01-01" , "2016-02-30" , "offer 46"

客户12的并发优惠少于4个，但客户106拥有4个并发优惠 - 从20日到22日将是4个并发报价

       15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 01 02 03 04 05 
33  12  |--------------------------------------------|
34  12           |-----------|
35  12                |------------------------------|
36  12                                                    |---------------
43 106  |--------------------------------------------|
44 106           |-----------|
45 106                |------------------------------|
56 106  |-----------------------------------------------------------------
                      ^^^^^^^^
                      106 has 4 concurrent offers

Answer 1

select custid, count(offerid) from offer group by custid having count(offerid)  > 3

Answer 2

要获取客户的优惠计数，请使用此查询。

select count(offerid) from offer where custid = ?;

或列出所有至少有4个优惠的客户：

select distinct o1.custid from offer o1 where (select count(o2.offerid) from offer o2 where o1.custid = o2.custid) > 3;

如果您还想检查重叠的日期间隔，请将其添加到select count（）查询中：

select distinct o1.custid from offer o1 where
 (select count(o2.offerid) from offer o2 where
    o1.custid = o2.custid
    and o1.start_date <= o2.end_date
    and o1.end_date >= o2.start_date) > 3;

Answer 3

Select custid, count(*) as numOfOrders from offer
where NOW() between inidate and enddate 
group by custid
having numOfOrders > 3

Answer 4

E.g。

SELECT x.customer_id 
  FROM my_table x 
  JOIN my_table y 
    ON y.customer_id = x.customer_id 
   AND y.start_date <= x.end_date 
   AND y.end_date >= x.start_date 
   AND y.offer_id >= x.offer_id 
 GROUP 
    BY x.offer_id 
 HAVING COUNT(*) >= 4;

SQL。我需要知道一些客户是否有超过3个并发优惠

4 个答案: