SQL Server 2005从字符串中提取日期

Question

I have a view I am creating and I want to group by an extracted date from a column that has a date and time. This is where I am....

SELECT     
    ClockCode AS MOnum, SUM(Actual_Hrs) AS Runtothours, TStamp
FROM
    dbo.Raw_Booking
WHERE     
   (Actual_Hrs > 0) AND (ClockCode LIKE 'MO%') 
   AND (TStamp > CONVERT(DATETIME, '2013-01-01 00:00:00', 102))
GROUP BY 
   ClockCode, TStamp

so while I have it grouped by the TStamp column there is a record for each one based on the time... I am looking to get a total amount of run time for each order by date.

The TStamp column is formatted as:

2013-01-02 08:18:47.000

Answer 1

If you can change your schema, store it as a date to begin with. Otherwise, change your group by clause to something similar to...

GROUP BY CAST(TStamp AS DATE)

EDIT: Forgot you were in SQL 2005. You can still do something like the following, but keep in mind this should be considered an ugly, short-term, workaround. All the comments in this thread about redesigning are completely valid and should be pursued...

GROUP BY SUBSTRING(TStamp, 0, 11)

Answer 2

SELECT ClockCode AS MOnum
     , SUM(Actual_Hrs) AS Runtothours
     , TStampDate
FROM dbo.Raw_Booking
     CROSS APPLY (
         SELECT CONVERT(datetime, TStamp, 102) AS TStampDateTime
     ) AS CA1
     CROSS APPLY (
         SELECT DATEADD(day, DATEDIFF(day, 0, TStampDateTime), 0) AS TStampDate
     ) AS CA2
WHERE Actual_Hrs > 0 
      AND ClockCode LIKE 'MO%'
      AND TStampDateTime > CONVERT(DATETIME, '2013-01-01 00:00:00', 102))
GROUP BY ClockCode
        ,TStampDate