Math in forms

[lmossolle]

I have an access db, I have 2 tables and forms, Issued and Forms. I want to
have a subtraction from the table of Issued, Column Quanity Issued to
subtract from Table forms, Column Quantity. Then have it update the Forms
Table, Column Quanity. Could some one please assist? This will be done from
form inputs.

 

[Damian S]

Hi,

I don't think you want to be calculating values to store in a table like
this. It is generally a poor design choice to store a value that you could
calculate.

You could easily work out the number of items by summing those in the
Quantity column and subtracting those in the Issued column.

Hope this helps.

Damian.

 

[lmossolle]

So I should make an additionl column for this? I appreciate the feedback. Or
should i simply have a querry to run and have the user subtract the forms
issued?

Thanks!

Lee

 

[John Vinson]

I have an access db, I have 2 tables and forms, Issued and Forms. I want to
have a subtraction from the table of Issued, Column Quanity Issued to
subtract from Table forms, Column Quantity. Then have it update the Forms
Table, Column Quanity. Could some one please assist? This will be done from
form inputs.

How are the Issued and Forms tables related? Do they have some field
in common?

If so, you can create a Query joining the two; in a vacant Field cell
you can type

QuantityResult: [Forms].[Quantity] - [Issued].Quantity]

This field can be used as the control source of a textbox on the form.

Or, you can use the same expression in the Control Source of a textbox
on the form.

If you do not have a linking field - how can you ascertain WHICH
record in Issued should be subtracted from WHICH record in Forms?

John W. Vinson[MVP]