Question

是否可以将这两个查询合并为一个？现在，我运行了2个单独的查询，向我展示：

用户名及其打开的问题数
用户名及其关闭的问题数

未解决的问题：

SELECT FirstName +' ' + LastName AS 'UserName', COUNT(u.UserID) AS IssuesOpened
FROM Users u
LEFT OUTER JOIN Issues i ON i.CreatedByUserID = u.UserID
WHERE i.DateCreated BETWEEN '06/30/2012 23:59:59' AND '07/01/2013 00:00:01'
GROUP BY LastName, FirstName

结果看起来如此：

UserName | IssuesOpened
-----------------------
User 1      10
User 2      8
User 3      55

已解决的问题：

SELECT FirstName +' ' + LastName AS 'UserName', COUNT(u.UserID) AS IssuesClosed
FROM Users u
LEFT OUTER JOIN Issues i ON i.ResolvedByUserID = u.UserID
WHERE ResolvedDate BETWEEN '06/30/2012 23:59:59' AND '07/01/2013 00:00:01'
GROUP BY LastName, FirstName

结果看起来如此：

UserName | IssuesClosed
-----------------------
User 1      8
User 2      2
User 3      40

我想加入这两个问题来解决这个问题：

UserName | IssuesOpened | IssuesClosed
--------------------------------------
User 1      10              8
User 2      8               2
User 3      55              40

我尝试了一些丑陋的东西，比如：

SELECT FirstName + ' ' + LastName AS UserName,
    (SELECT COUNT(u.UserID)
    FROM Users u
    LEFT OUTER JOIN Issues i ON i.ResolvedByUserID = u.UserID
    WHERE ResolvedDate BETWEEN '06/30/2012 23:59:59' AND '07/01/2013 00:00:01')
    AS IssuesClosed,
    (SELECT COUNT(u.UserID)
        FROM Users u
        LEFT OUTER JOIN Issues i ON i.CreatedByUserID = u.UserID
        WHERE i.DateCreated BETWEEN '06/30/2012 23:59:59' AND '07/01/2013 00:00:01')
    AS IssuesOpened
FROM Users u
GROUP BY FirstName, LastName

但是因为我删除了每个子查询中的GROUP BY子句，所以它只返回总行数。

更新

由于我无法将数据加载到SqlFiddle中（查询窗口和架构窗口都只能容纳8000个字符），我想出了一些关于我的结果与sgeddes结果的截图：

我的结果 PhotoBucket Link to larger image: My Results

sgeddes结果 SGEDDES Results

有一件事对我来说就是如果你注意到sgeddes结果，最后一行，用户“Web ***”有449表示“已关闭”。这是不可能的，因为该用户（Web ***）是我们如何确定客户如何通过我们的网站解决问题的占位符。这个虚假用户无法访问我们的系统，也无法关闭任何票证。

Answer 1

这可以使用COUNT与CASE：

一起使用

SELECT FirstName +' ' + LastName AS 'UserName', 
    COUNT(CASE WHEN i.DateCreated BETWEEN '06/30/2012 23:59:59' AND '07/01/2013 00:00:01' 
               THEN 1 END) AS IssuesOpened, 
    COUNT(CASE WHEN ResolvedDate BETWEEN '06/30/2012 23:59:59' AND '07/01/2013 00:00:01' 
               THEN 1 END) AS IssuesClosed
FROM Users u
    LEFT OUTER JOIN Issues i ON i.CreatedByUserID = u.UserID OR i.ResolvedByUserID = u.UserID
GROUP BY LastName, FirstName

这将返回所有用户 - 因此有些人可能会计为0.如果您不想要所有用户，则可以使用WHERE上方OR添加GROUP BY条件。 1}}。在执行此操作时，您否定了需要OUTER JOIN的原因，因此我会将其更改为INNER JOIN。

SELECT FirstName +' ' + LastName AS 'UserName', 
    COUNT(CASE WHEN i.DateCreated BETWEEN '06/30/2012 23:59:59' AND '07/01/2013 00:00:01' 
           THEN 1 END) AS IssuesOpened, 
    COUNT(CASE WHEN ResolvedDate BETWEEN '06/30/2012 23:59:59' AND '07/01/2013 00:00:01' 
           THEN 1 END) AS IssuesClosed
FROM Users u
    INNER JOIN Issues i ON 
         i.CreatedByUserID = u.UserID OR i.ResolvedByUserID = u.UserID
WHERE i.DateCreated BETWEEN '06/30/2012 23:59:59' AND '07/01/2013 00:00:01'
    OR ResolvedDate BETWEEN '06/30/2012 23:59:59' AND '07/01/2013 00:00:01'
GROUP BY LastName, FirstName

BTW - 在处理日期字段时，我建议使用＆gt; =和＆lt;因此而不是BETWEEN。

Answer 2

我会这样做：

取消隐藏指定时间段内的所有Issue数据，以便每行只包含用户ID和用户造成的状态更改（'Opened'或'Closed'）
旋转结果集，计算每个用户ID的状态更改。
将数据集加入Users以访问这些名称。

这是我在实施上述过程中想出的：

WITH unpivoted AS (
  SELECT
    x.UserID,
    x.IssueStatusChange
  FROM Issues
  CROSS APPLY (
    VALUES
      (CreatedByUserID,  'Opened', DateCreated),
      (ResolvedByUserID, 'Closed', ResolvedDate)
  ) x (UserID, IssueStatusChange, ChangeDate)
  WHERE x.ChangeDate BETWEEN '06/30/2012 23:59:59'
                         AND '07/01/2013 00:00:01'
),
pivoted AS (
  SELECT
    UserID,
    Opened,
    Closed
  FROM unpivoted
  PIVOT (COUNT(IssueStatusChange)
  FOR IssueStatusChange IN (Opened, Closed)) p
),
SELECT
  UserName = u.FirstName + ' ' + u.LastName,
  p.Opened,
  p.Closed
FROM Users u
INNER JOIN pivoted p ON u.UserID = p.UserID
;

如果有人感兴趣的话，这个查询还有一个SQL Fiddle demo，虽然测试数据集不是很显着（但是可以看到工作中的东西）。

使用不同的WHERE条件加入查询结果

2 个答案: