Question

I have a table with two DATETIME columns:

Column1              Column2
1/1/1900 12:20:45    1/1/1900 23:22:25
1/1/1900 09:00:00    1/1/1900 18:10:30
…                    …

(Times are in the format HH:MM:SS.)

I want to take a total of column 1 and total of column 2. If the table had only the two rows shown above, the expected outcome would be:

Column1              Column2 
1/1/1900 21:20:45    1/1/1900 41:32:55

Note that hours, minutes, and seconds should not exceeded 60.

How do I sum these columns in SQL Server 2000?

Answer 1

this will give you what you are after:

CREATE TABLE #Times
(
     Column1 datetime
    ,Column2 datetime
)

INSERT INTO #Times VALUES ('1/1/1900 12:20:45',    '1/1/1900 23:22:25')
INSERT INTO #Times VALUES ('1/1/1900 09:00:00',    '1/1/1900 18:10:30')

SELECT
     CONVERT(varchar(10),dateadd(day,datediff(day,0,dt2.MinColumn1),0),101)
         +' '
         +CASE WHEN TotalSecondsColumn1/3600>60 then '60' ELSE CONVERT(varchar(2),TotalSecondsColumn1/3600) END
         +':'
         +CASE WHEN (TotalSecondsColumn1-(TotalSecondsColumn1/3600*3600))/60 >60 then '60' ELSE CONVERT(varchar(2),(TotalSecondsColumn1-(TotalSecondsColumn1/3600*3600))/60) END
         +':'
         +CASE WHEN TotalSecondsColumn1-((TotalSecondsColumn1/3600*3600)+(((TotalSecondsColumn1-(TotalSecondsColumn1/3600*3600))/60)*60)) >60 then '60' ELSE CONVERT(varchar(2),TotalSecondsColumn1-((TotalSecondsColumn1/3600*3600)+(((TotalSecondsColumn1-(TotalSecondsColumn1/3600*3600))/60)*60))) END
     AS Column1
    ,CONVERT(varchar(10),dateadd(day,datediff(day,0,dt2.MinColumn2),0),101)
         +' '
         +CASE WHEN TotalSecondsColumn2/3600>60 then '60' ELSE CONVERT(varchar(2),TotalSecondsColumn2/3600) END
         +':'
         +CASE WHEN (TotalSecondsColumn2-(TotalSecondsColumn2/3600*3600))/60 >60 then '60' ELSE CONVERT(varchar(2),(TotalSecondsColumn2-(TotalSecondsColumn2/3600*3600))/60) END
         +':'
         +CASE WHEN TotalSecondsColumn2-((TotalSecondsColumn2/3600*3600)+(((TotalSecondsColumn2-(TotalSecondsColumn2/3600*3600))/60)*60)) >60 then '60' ELSE CONVERT(varchar(2),TotalSecondsColumn2-((TotalSecondsColumn2/3600*3600)+(((TotalSecondsColumn2-(TotalSecondsColumn2/3600*3600))/60)*60))) END
     AS Column1
    FROM #Times t
        INNER JOIN (SELECT
                         SUM(DATEDIFF(second,CONVERT(datetime,LEFT(CONVERT(char(23),Column1,121),10)),Column1)) AS TotalSecondsColumn1
                        ,SUM(DATEDIFF(second,CONVERT(datetime,LEFT(CONVERT(char(23),Column2,121),10)),Column2)) AS TotalSecondsColumn2
                        FROM #Times
                   ) dt ON 1=1
        INNER JOIN (SELECT
                         MIN(Column1) AS MinColumn1
                        ,MIN(Column2) AS MinColumn2
                        FROM #Times
                   ) dt2 ON 1=1
    WHERE t.Column1=dt2.MinColumn1

OUTPUT:

Column1             Column1
------------------- -------------------
01/01/1900 21:20:45 01/01/1900 41:32:55

(1 row(s) affected)

However, this will accurately sum the times, incrementing the day, month, and year as well:

SELECT
     DATEADD(second,dt.TotalSecondsColumn1,dateadd(day,datediff(day,0,dt2.MinColumn1),0)) AS Column1
    ,DATEADD(second,dt.TotalSecondsColumn2,dateadd(day,datediff(day,0,dt2.MinColumn2),0)) AS Column2
    FROM #Times t
        INNER JOIN (SELECT
                         SUM(DATEDIFF(second,CONVERT(datetime,LEFT(CONVERT(char(23),Column1,121),10)),Column1)) AS TotalSecondsColumn1
                        ,SUM(DATEDIFF(second,CONVERT(datetime,LEFT(CONVERT(char(23),Column2,121),10)),Column2)) AS TotalSecondsColumn2
                        FROM #Times
                   ) dt ON 1=1
        INNER JOIN (SELECT
                         MIN(Column1) AS MinColumn1
                        ,MIN(Column2) AS MinColumn2
                        FROM #Times
                   ) dt2 ON 1=1
    WHERE t.Column1=dt2.MinColumn1

OUTPUT:

Column1                 Column2
----------------------- -----------------------
1900-01-01 21:20:45.000 1900-01-02 17:32:55.000

(1 row(s) affected)