Access two records simultaneously and do calculations

[Arif15]

We have a project that is on Access. I have a table called T_RENT(where there is the issue of location, start date of rental ...) and another called T_COPY(where there are the films in their chosen media (DVD, Blu-ray, K7 ...), the quantity, price per day ...).

At first, I want in my form, I hit a new record on T_RENT(it has no problem), I enter the start date of hire, the selected film and media. And that's where it thickens. I wish now that the price of renting the movie (depending on the chosen medium: dvd, k7 ...) fits into the table T_RENT depending on what was entered at the beginning (I do not want just that it shows me, I want that I write it in the corresponding field T_RENT.RENT_PRICE). Second, once that is done, I hope that the record (once you click a button "register") field COPY_QTE table T_COPY down 1 (decrement) automatically selected by film and media chosen (as it will be removed from the reserve, because it will be rented).

I really hope you can help me.

Problem: I wanted access to two records simultaneously (or successively) and do calculations inside a table through a form

[absolute55]

I do not see your table in any table T_client this seems odd.

Regarding the problem that prevents you from sleeping! I suggest you see if using a principal form and a subform there is no way to resolve this concerns. I am confident that, yes, but not make you a good service that give the easy solution is you must learn not true.

[Reegan]

Regarding the specifications, it is very thin compared to the only constraint that we have though given, the presentation of your subject appears to me to be away ()

Present us your relational model with different tables that will allow us to better return to your subject.

As for displaying multiple records: absolute55 proposed on the form and subform that is quite adequate.

Moreover, they give you may be ideas for tracking the location of your videos

[Arif15]

Yes, but my worry is that I want to do calculations inside tables. How can you put a field in a table (here T_RENT.RENT_PRICE) where I can put something. But here I am, therefore lock the field and how that fits inside the field T_COPY.COPY_PRICEDAY. Then the recording I want a new calculation is done in T_COPY.COPY_QTY knowing that T_RENT.COPY_FILM_ID = T_COPY.COPY_FILM_ID and T_RENT.COPY_SUPPORT_ID = T_COPY.COPY_SUPPORT_ID and calculation would T_COPY.COPY_QTY (new) = (T_COPY.COPY_QTY (before) -1)

For clarity, this is all my relationships (I did not give everything not to confuse)

I do not want someone to do it myself but I do not really know how to do a calculation inside a table because when a field as a source field name of the table is not going to make a calculation.