Question

我正在编写一个查询，该查询应该向一组用户显示，他/她收到了哪些电子邮件以及该电子邮件是否打开。

这是查询的结果：

Product     |   Year    |   Month   |   SendTime    |   UserId      |   EmailTitle      |   Open
That one    |   2018    |   11      |   2018-11-23  |   1000756     |   JoinUs          |   1   
That one    |   2018    |   11      |   2018-11-25  |   1000756     |   JoinUs          |   0   
That one    |   2019    |   1       |   2019-01-04  |   1000756     |   Need Help?      |   0   
That one    |   2019    |   4       |   2019-04-07  |   1000756     |   Win Back        |   0   
That one    |   2019    |   4       |   2019-04-10  |   1000756     |   A gift to you   |   0

我的问题是，用户每月可以多次收到同一封电子邮件，并且只打开其中一封。一个例子是JoinUs EmailTitle，它在第23和25天收到，但只有23封邮件是打开的。

因此，在这种情况下，当我发送两封相等的电子邮件时，我只需要显示一行，而我只需要显示打开的那一行即可。

SELECT  S.Product, 
        YEAR(S.SendTime) [Year],
        MONTH(S.SendTime) [Month],
        S.SendTime SendTime, 
        S.UserId,
        M.EmailName,
        CASE WHEN Mo.ContactID IS NOT NULL THEN 1 ELSE 0 END [Open]
FROM MailSend S
JOIN CommMapping2 M on M.EmailName = S.EmailName
LEFT JOIN MailOpen Mo ON Mo.JobId = S.JobId AND Mo.BatchID = S.BatchID AND Mo.ContactID = S.ContactID 
WHERE S.UserId IS NOT NULL AND S.UserId = '1000756'

Answer 1

您可以使用rownumber和partition和userid制作EmailTitle。这样，在收到两封电子邮件的情况下，您只会收到一封打开的电子邮件。

with cte as (
SELECT  S.Product, 
        YEAR(S.SendTime) [Year],
        MONTH(S.SendTime) [Month],
        S.SendTime SendTime, 
        S.UserId,
        M.EmailName,
        CASE WHEN Mo.ContactID IS NOT NULL THEN 1 ELSE 0 END [Open],
        ROW_NUMBER() over (partition by UserId,  EmailTitle order by  CASE WHEN Mo.ContactID IS NOT NULL THEN 1 ELSE 0 END desc) as number 
FROM MailSend S
JOIN CommMapping2 M on M.EmailName = S.EmailName
LEFT JOIN MailOpen Mo ON Mo.JobId = S.JobId AND Mo.BatchID = S.BatchID AND Mo.ContactID = S.ContactID 
WHERE S.UserId IS NOT NULL AND S.UserId = '1000756'
)
select *
from cte 
where number = 1

按特定条件将sql结果分组

1 个答案: