>

>UPDATE Client
> SET DayBetweenFirstDateSecondDate=
>  (SELECT SUM(Temp.SecondValue)/3600.0/8 AS HourValue
>  FROM (SELECT DATEDIFF(SECOND,
>   CASE WHEN BusinessTime.Start>Client.FirstDate THEN BusinessTime.Start ELSE Client.FirstDate END,
>   CASE WHEN BusinessTime.[End]<Client.SecondDate THEN BusinessTime.[End] ELSE Client.SecondDate END) AS SecondValue
>   FROM BusinessTime
>   WHERE BusinessTime.NoProvince=84 AND BusinessTime.NoHoliday=0 AND 
>    ((BusinessTime.Start>=Client.FirstDate AND BusinessTime.Start<=Client.SecondDate) OR
>    (BusinessTime.[End]>=Client.FirstDate AND BusinessTime.[End]<=Client.SecondDate))) Temp)
>

>

Michel,

I haven't read all the messages in this thread so I don't know if you found an answer. If you haven't...

1) Can you post the estimated (or actual) execution plan
2) Can you post the structure for the Client and Business Time tables?

Thanks