Get data from previous entry

[jgrondin]

So far, when I scan a product, it records the current time with a Now function. What I need is to know how much time elapsed since my last scan by doing a Datediff function with the previous time recorded. My problem is that I can't manage to get the previous scan time.

I thought of two ways to do this.

1. Previous_scan = DMax("[Hours]", "Data", "Hours < Now()")
This does not work. If I change the criteria to "Hours <= Now()", it gives me the current time as if my function could not find other times recorded than the current time.

2. My second idea was to use a Dlookup and use my autonumber to look for "the current autonumber - 1" in order to get the previous time recorded. But I can't manage to create the variable in order to do this.


Anyone has any idea to solve this ? I've been working on this for 2 days already and it's getting on my nerves.

Thank you so much !

[jgrondin]

Here is a part of my actual code.


"Product" is the product number when an item is scanned.
"Hours" is the current time when an item is scanned.
I want "Hours_fini sh" to be the time of the previous scan.

If Product <> 0 Then
Hours = Now()
End If

If Product <> 0 Then
Previous_scan = DMax("[Hours]", "Data", "Hours < Now()")
End If

[Rabbit]

Use the first method. But you need to limit on some sort of product id. What you have there returns the max of all the products. I assume you only want the max of the product you're scanning.