Help With a DATETIME Query

[Shaun]

Hi,

I have a table called Bookings which has two important columns;
Booking_Start_Date and Booking_End_Date. These columns are both of type
DATETIME. The following query calculates how many hours are available
between the hours of 09.00 and 17.30 so a user can see at a glance how many
hours they have unbooked on a particular day (i.e. 8.5 hours less the time
of any bookings on that day). However, when a booking spans more than one
day the query doesn't work, for example if a user has a booking that starts
on day one at 09.00 and ends at 14.30 on the next day, the query returns 3.5
hours for both days. Any help here would be greatly appreciated.

SELECT 8.5 - (SUM(((DATE_FORMAT(B.Booking_End_Date, '%k') * 60 ) +
DATE_FORMAT(B.Booking_End_Date, '%i')) - ((DATE_FORMAT(B.Booking_Start_Date,
'%k') * 60 ) + DATE_FORMAT(B.Booking_Start_Date, '%i'))) / 60) AS
Available_Hours FROM WMS_Bookings B WHERE B.User_ID = '16' AND
B.Booking_Status <> '1' AND NOT ( '2003-10-07' <
DATE_FORMAT(Booking_Start_Date, "%Y-%m-%d") OR '2003-10-07' >
DATE_FORMAT(Booking_End_Date, "%Y-%m-%d") )

Thanks for your help

 

[Douglas J. Steele]

What language are you doing this in? VBA (or at least the version of VBA
Access uses) doesn't have a DATE_FORMAT function, and the Format function it
does have doesn't use % signs in its parameters.

If you are doing this from within Access, my advice would be to write a
function that you can pass 2 dates to, and have it do the calculation for
you.