Durchschnitt zwischen zwei Datetime-Spalten

Question

Ich habe die folgende Abfrage, wo ich versuche, den Durchschnitt zwischen zwei DateTime Spalten zurückzugeben.

Mein Problem ist es will mich nach SoftwarePackage1_VersionNumbers.EnvShortName gruppieren, was ich nicht tun möchte.

SELECT DBO.softwarepackage1_versionnumbers.envshortname                     AS [Environment Name], 
     DBO.softwarepackage1_versionnumbers.currentversionnumber                   AS [SoftwarePackage1 Current Version Number], 
     DBO.softwarepackage1_versionnumbers.currentbuildname                    AS [Current SoftwarePackage1 Build], 
     DBO.softwarepackage1_versionnumbers.currentlastassociatedchangeset                AS [Last Associated Changeset], 
     DBO.softwarepackage1_versionnumbers.deploymentdate                    AS [SoftwarePackage1 Deployment Date], 
     DBO.softwarepackage2_versionnumbers.currentsoftwarepackage2displayedversionnumber             AS [SoftwarePackage2ector Displayed Version Number], 
     DBO.softwarepackage2_versionnumbers.currentsoftwarepackage2fullversionnumber              AS [SoftwarePackage2ector Full Version Number], 
     DBO.softwarepackage2_versionnumbers.currentlastfilewritedatetime                 AS [SoftwarePackage2ector Last File Write Time], 
     DBO.softwarepackage2_versionnumbers.deploymentdate                    AS [SoftwarePackage2ector Deployment Date], 
     Avg(Datediff(MINUTE, DBO.softwarepackage1_versionnumbers.modifieddatetime, DBO.softwarepackage2_versionnumbers.modifieddatetime)) AS [Last Version Check (UTC)] 
FROM DBO.softwarepackage1_versionnumbers 
     FULL OUTER JOIN DBO.softwarepackage2_versionnumbers 
        ON DBO.softwarepackage1_versionnumbers.envid = DBO.softwarepackage2_versionnumbers.envid 
     FULL OUTER JOIN DBO.systemenvironments 
        ON DBO.softwarepackage1_versionnumbers.envid = DBO.systemenvironments.envid 
WHERE (DBO.softwarepackage1_versionnumbers.deleted = '0') 
     AND (DBO.softwarepackage2_versionnumbers.deleted = 0) 
     AND (DBO.systemenvironments.envtype = 'Development') 

Answer 1

versuchen, etwas ähnliches zu einem des Verfahrens in dieser Abfrage:

SELECT name, create_date, modify_date, 
    CONVERT(DATETIME,(CONVERT(FLOAT,create_date)+CONVERT(FLOAT,modify_date))/2) AS AvgDate1, 
    DATEADD(S,DATEDIFF(S,create_date,modify_date)/2.,create_date) AS AvgDate2 
FROM sys.objects 

Answer 2

Für den Durchschnitt nur zwei Termine:

DECLARE @date2 DATETIME = GETDATE(), @date1 DATETIME = DATEADD(DAY,-7,GETDATE()); 

SELECT 
    CASE WHEN @date1<@date2 
     THEN DATEADD(SECOND,DATEDIFF(SECOND,@date1,@date2)/2,@date1) 
     ELSE DATEADD(SECOND,DATEDIFF(SECOND,@date2,@date1)/2,@date2) 
    END;