Question

I’d appreciate if someone could help me with this SQL statement. I currently have this:

select sum(datediff(second, [date1], [date2])) from [MyTable] where <condition>

But I need to refine this selection, i.e. if the difference between dates is greater than @MaxDiffSecs then the @MaxDiffSecs should be used for summation instead. I tried looking into the MIN operator but it has only one parameter, where I’d expect at least 2 to get the minimum of.

Well, anyway, thanks in advance. (I guess you can tell that I’m not really efficient at SQL 🙂

Answer 1

SELECT SUM(
    CASE WHEN DATEDIFF(second, [date1], [date2]) > @MaxDiffSecs THEN @MaxDiffSecs
    ELSE DATEDIFF(second, [date1], [date2]) END)
FROM [MyTable] 
WHERE <condition>

This is off the top of my head, not sure if the CASE works inside a SUM

If that syntax does not work you could use a CTE

WITH ValuesToSum AS (
    SELECT CASE WHEN DATEDIFF(second, [date1], [date2]) > @MaxDiffSecs THEN @MaxDiffSecs
        ELSE DATEDIFF(second, [date1], [date2]) END AS TheValue
    FROM [MyTable]
    WHERE <condition>
)

SELECT SUM(TheValue) FROM ValuesToSum