Question

我正在尝试使用MSSQL Express 2005获取在日期范围内收到的电子邮件数量。我已经管理了那么多，但现在我想将数据拆分成用它完成的工作。

这是我到目前为止所得到的：

SELECT EmailAddress, COUNT(EmailAddress) 
  FROM mails 
  WHERE ReceivedTime >= DATEADD(DAY, -7, GETDATE()) 
  GROUP BY EmailAddress
    HAVING COUNT(EmailAddress) > 10

这给了我一个上周邮寄超过10次的地址列表，但是我们还有另一个列告诉我们邮件发生了什么。我正在努力实现这样的目标：

SELECT EmailAddress, 
  COUNT(ActionTaken WHERE ActionTaken="Deleted") AS Deleted,
  COUNT(ActionTaken WHERE ActionTaken="Replied") AS Replied,
  COUNT(ActionTaken WHERE ActionTaken="Read") AS Read,
  COUNT(EmailAddress) AS Total
  FROM mails 
  WHERE ReceivedTime >= DATEADD(DAY, -7, GETDATE()) 
  GROUP BY EmailAddress
    HAVING COUNT(EmailAddress) > 10

我正在寻找这些行的结果集：

 EmailAddress     | Deleted | Replied | Read | Total
 ---------------------------------------------------
 user1@domain.com | 4       | 5       | 3    | 12
 user2@domain.com | 2       | 6       | 3    | 11

我很确定它与使用OVER（PARTITION BY）子句有关，但我遇到了障碍。我意识到ActionTaken字段并不理想，但我没有构建它！

Answer 1

对字符串文字使用单引号，因此无论QUOTED_IDENTIFIER设置如何，它都可以正常工作。

SELECT EmailAddress,
       Sum(CASE WHEN ActionTaken = 'Deleted' THEN 1 ELSE 0 END) AS Deleted,
       Sum(CASE WHEN ActionTaken = 'Replied' THEN 1 ELSE 0 END) AS Replied,
       Sum(CASE WHEN ActionTaken = 'Read' THEN 1 ELSE 0 END)    AS [Read],
       Count(EmailAddress) AS Total
FROM   mails
WHERE  ReceivedTime >= Dateadd(DAY, -7, Getdate())
GROUP  BY EmailAddress
HAVING Count(EmailAddress) > 10

Answer 2

SELECT EmailAddress,
       COUNT(CASE WHEN ActionTaken = 'Deleted' THEN ActionTaken END) AS Deleted,
       COUNT(CASE WHEN ActionTaken = 'Replied' THEN ActionTaken END) AS Replied,
       COUNT(CASE WHEN ActionTaken = 'Read' THEN ActionTaken END)    AS [Read],
       COUNT(EmailAddress) AS Total
FROM mails
WHERE ReceivedTime >= DATEADD(DAY, -7, GETDATE())
GROUP BY EmailAddress
HAVING COUNT(EmailAddress) > 10

在日期范围内选择COUNT

2 个答案: