Access Date calculation

We need to track how often a book has been loaned. We enter the dates
and need an automatic calculation how often in the preceeding 12 months
it has been taken out. box 1: today's date box 2: loaned n+1
How do I go about this please?
Lindie

re: Access Date calculation

<Lindie@magichans.com> wrote
[color=blue]
> We need to track how often a
> book has been loaned. We enter
> the dates and need an automatic
> calculation how often in the pre-
> ceeding 12 months it has been
> taken out.[/color]
[color=blue]
> box 1: today's date box 2: loaned n+1[/color]
[color=blue]
> How do I go about this please?[/color]

If you will clarify what data you _keep_ about the book and loans, not just
what you want to _return/calculate_, someone may be able to offer a useful
suggestion.

If you only have one record per loan and it contains the checkout date,
you'll insert today's date as criteria for the date field, and use the count
function on a field that is not null in any record... but you may be using
different information to track book loans.

Larry Linson
Microsoft Access MVP

re: Access Date calculation

Thank you Larry for suggesting some more clarity from me.
A particular event occurs: a book is loaned
this happens on a particular date DateY
This book has also been loaned on previous dates

What we need is when we enter date Y is for the total number of times
the book has been loaned out in the previous 12 months.
something like [number of loans over (today-12 months)]
Lindie

re: Access Date calculation

Larry,

Just thought through your suggestion about using the date. This we
could do because there is a date every time a book is loaned. I am
stuck though as to where to go from there. You mentioned there not
being any '0' records but there will be. Some weeks a particular book
will remain on the shelf.
Using a count function- whatever that is- may not work.
Sorry to be more than a little dense.
L