sum

[Guest]

I am creating an Access database and I would like a field in a table to have
a default that automatically gives the numerical sum of two other fields in
the same table, BUT also maintain the ability to edit the field. I would
like the field to just give the sum as a default, not a fixed value.
Example: Field 1 is "A Amount" and Field 2 is "B Amount" and I would like the
sum of "A Amount" and "B Amount" to show up in Field 3, but be
editable/overwritable. It would not work for me to put this expression into
the Default Value for Field 3 in the table. Is this possible?

 

[Guest]

Yes it is possible there are a "very" few times when it's a good idea. Most
of the time you should run the calcultation as and when you need it in a form
or query or report.

The reason for this is that if you store a calculation such as "age.
Today - date of birth
The is will only be right today unless you do the calculation every day
(which would take some time on a large DB).

Open a new query based on the table and use the wizard (right click - build)
to help you with the calculation

Good luck