mysql - 根据条件计数和排除

Answer 1

好吧，您的问题的简化是计算唯一的 MemberId

选择计数（*）从（
   从 SampleDidYouBuy 中选择 *
   WHERE SampleID = {YourSampleID}
   按会员 ID 分组
) 作为样本；

Answer 2

MySQL 允许在聚合函数中使用表达式。看看这个：http ://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_count

所以你的 SQL 语句应该如下（如果我正确地理解了你的问题？）：

SELECT MemberID, COUNT(DidYouBuy=0) as 'No-s', COUNT(DidYouBuy=1) as 'Yes-s'
FROM SampleDidYouBuy
GROUP BY MemberID

如果您希望收到每个样本的 No-s 数量：

SELECT SampleID, MemberID, COUNT(DidYouBuy=0)
FROM SampleDidYouBuy
GROUP BY SampleID, MemberID

Answer 3

如果我理解您的问题，您可以尝试此查询以查找未变为“是”的唯一编号的数量

仅限会员ID

SELECT 
  `MemberID`, COUNT(*) 
FROM `SampleDidYouBuy` 
GROUP BY `MemberID` 
HAVING MAX(`DidYouBuy`) = 0

输出：

+----------+----------+
| MemberID | COUNT(*) |
+----------+----------+
|       23 |        1 |
|       32 |        2 |
|       40 |        2 |
+----------+----------+

对于 MemberID 和 sampleID

SELECT 
  `MemberID`, `sampleID`, COUNT(*) 
FROM `SampleDidYouBuy` 
GROUP BY `MemberID`, `sampleID` 
HAVING MAX(`DidYouBuy`) = 0

输出

+----------+----------+----------+
| MemberID | sampleID | COUNT(*) |
+----------+----------+----------+
|       23 |    23182 |        1 |
|       24 |    23214 |        2 |
|       27 |    23184 |        3 |
|       27 |    23224 |        2 |
|       27 |    23254 |        2 |
|       27 |    23259 |        2 |
|       32 |    23184 |        2 |
|       40 |    23181 |        2 |
+----------+----------+----------+

Answer 4

试试下面的查询： -

select 
  (select count(MemberID) from SampleDidYouBuy where DidYouBuy='1' group by MemberID) as yesCount,
  (select count(MemberID) from SampleDidYouBuy where DidYouBuy='0' group by MemberID) as noCount 
from SampleDidYouBuy;

Answer 5

更新：

select a.MemberId,
       count(distinct a.SampleId) as unique_nos
  from SampleDidYouBuy a
 where a.DIdYouBuy = 0
   and not exists (select 1 
                     from SampleDidYouBuy b
                    where b.MemberId = a.MemberId
                      and b.SampleId = a.SampleId
                      and b.DidYouBuy = 1)
 group by a.MemberId;

小提琴演示。

要获取所有列的行，

select SampleDidYouBuyID, sampleid, MemberID, DIdYouBuy, DateAdded
  from SampleDidYouBuy a
 where a.DIdYouBuy = 0
   and not exists (select 1 
                     from SampleDidYouBuy b
                    where b.MemberId = a.MemberId
                     and b.SampleId = a.SampleId
                     and b.DidYouBuy = 1)
 group by memberid, sampleid
 order by MemberID,sampleid;

从您的预期输出中不太清楚，应该显示哪一个重复行。