DSum Syntax question

[Mark Stone]

I am trying to have a text box called, Placesleft, do the
following calculation:

Return the total number of bookings from
tblbookings.numberOfPeople where the holiday number = the
holiday number from frmBookings.HolidayRef

I understand I need to use the dsum but cant get the
syntax correct.

Thanks for any help given.

 

[fredg]

I am trying to have a text box called, Placesleft, do the
following calculation:

Return the total number of bookings from
tblbookings.numberOfPeople where the holiday number = the
holiday number from frmBookings.HolidayRef

I understand I need to use the dsum but cant get the
syntax correct.

Thanks for any help given.

In an unbound control on the form "frmBookings":

=DSum("[NumberOfPeople"]","tblBookings","[HolidayNumber] = " &
Me![HolidayRef])

The above assumes the HolidayNumber field is a Number datatype, i.e.
12345.
If HolidayNumber is a Text datatype, i.e. BAZ12345 or 12-345, then
use:
"[HolidayNumber] ] = '" & Me![HolidayRef] & "'")