使用日期时间 SQL 2008 R2 时如何将查询与 AVG 查询结合使用答案

【问题标题】：How to Combine a query with a AVG query when using datetime SQL 2008 R2使用日期时间 SQL 2008 R2 时如何将查询与 AVG 查询结合使用
【发布时间】：2013-11-26 12:20:26
【问题描述】：

我正在尝试将两个查询组合在一起，但我遇到了麻烦，因为它是一个日期时间列。现在我有一个查询可以找到所有用户+那里最慢和最快的“段”时间，但我还需要找到下面的平均段时间是我现在使用的两个查询，哪个工作但我需要它在一个查询我正在制作的报告。

谢谢

托马斯·詹姆斯

DECLARE 
@vnuID int = 1212,
@StartDate DateTime = '30/10/2013',
@EndDate DateTime = '26/11/2013'

SELECT DISTINCT usrFullName, MIN(CAST(tblTrace.trFinish - tblTrace.trStart AS TIME)) AS FastestUserSegmentTime,  
        MAX(CAST(tblTrace.trFinish - tblTrace.trStart AS TIME)) AS SlowestUserSegmentTime 
FROM tblTrace 
    INNER JOIN tblUsers ON usrID = tr_usrID
WHERE tr_vnuID = @vnuID AND trFinish IS NOT NULL AND tr_usrID IS NOT NULL AND trObjectType LIKE 'Segment%'  
        AND trStart BETWEEN @StartDate AND @EndDate 
GROUP BY usrFullName


SELECT AVG(TotalTime) AS AvgUserSegmentTime 
FROM (SELECT DateDiff(SECOND, tblTrace.trStart , tblTrace.trFinish) as 'TotalTime' 
        FROM tblTrace
        WHERE tblTrace.trFinish IS NOT NULL AND tblTrace.trObjectType LIKE 'Segment%' AND tblTrace.tr_vnuID = @vnuID 
        AND tblTrace.trStart BETWEEN @StartDate AND @EndDate ) as SubQuery

【问题讨论】：

标签： sql-server datetime average

【解决方案1】：

在功能上（即没有优化）你可以使用这样的东西：

DECLARE 
@vnuID int = 1212,
@StartDate DateTime = '30/10/2013',
@EndDate DateTime = '26/11/2013'

SELECT usrFullName, FastestUserSegmentTime, SlowestUserSegmentTime,
       (SELECT AVG(DateDiff(SECOND, tblTrace.trStart , tblTrace.trFinish)) 
        FROM tblTrace
        WHERE tblTrace.trFinish IS NOT NULL AND tblTrace.trObjectType LIKE 'Segment%' AND tblTrace.tr_vnuID = @vnuID 
        AND tblTrace.trStart BETWEEN @StartDate AND @EndDate) as AvgUserSegmentTime
FROM (
    SELECT usrFullName, 
           MIN(CAST(tblTrace.trFinish - tblTrace.trStart AS TIME)) AS FastestUserSegmentTime,  
           MAX(CAST(tblTrace.trFinish - tblTrace.trStart AS TIME)) AS SlowestUserSegmentTime 
    FROM tblTrace 
        INNER JOIN tblUsers ON usrID = tr_usrID
    WHERE tr_vnuID = @vnuID AND trFinish IS NOT NULL AND tr_usrID IS NOT NULL AND trObjectType LIKE 'Segment%'  
            AND trStart BETWEEN @StartDate AND @EndDate 
    GROUP BY usrFullName
) coreData

但是，我假设您希望tr_usrID 在所有情况下都不为空？在这种情况下，您可以使用它：

SELECT usrFullName, 
       CONVERT(TIME, DATEADD(s, MIN(SegmentTime))) as FastestUserSegmentTime,
       CONVERT(TIME, DATEADD(s, MAX(SegmentTime))) as SlowestUserSegmentTime,
       AVG(SegmentTime) as AvgUserSegmentTime
  FROM (
    SELECT usrFullName, 
           DateDiff(SECOND, tblTrace.trStart, tblTrace.trFinish) as SegmentTime
      FROM tblTrace INNER JOIN
           tblUsers  
        ON usrID = tr_usrID
     WHERE tr_vnuID = @vnuID 
       AND trFinish IS NOT NULL 
       AND tr_usrID IS NOT NULL 
       AND trObjectType LIKE 'Segment%'  
       AND trStart BETWEEN @StartDate AND @EndDate 
       ) coreData

【讨论】：