Software Licensing DB Development Help.

[rsmonkey]

Hi

I'm building a Software Licensing Database & I have come across this particular problem and i am not 100% sure which way would be the best way for me to solve it. So far I have created the database so that a user/software/license can be added to the system. The main form display's users information and below in a tabbed subform it displays the installed software on the machine. On the second tab it displays the license's attached to that machine. On each of these subforms its provides the user to add/delete software/license's however my problem is with error handling within the system. I have managed to make it so that a user can only selelct license's that are specific
Each License can cover anywhere from 1 to <x-amount> of pc's. What I want to be able to do is the user can select a license if their is 1 available and a small text box which denote's how many license's are available. So i know im going to need a license count which is easy enough using a SUM within a query. It is the error handling that im stuck on. I need to create a statement using the 'equal to or greater than' operator if possible saying
If NumberofLicenses >= then add license
Else If vbOKonly message - "Insufficient License's to cover this piece of software please purchase & add the new license to the system then try again"

Something along those lines.. I just dont know where this would go or how to write it! If anyone has a better way of achieving this.. fire away im open to ideas!

cheers

Ally

 

[CraigDolphin]

For the user to select a licence they need to use a control on a form. Let's assume that control is a combo box called cmboSelectLicense. I am also assuming you have a query called qryLicensesRemaining that lists Licenses by their ID, and shows the number of workstation allocations remaining for that license.

In the beforeupdate event of cmboSelectLicense use something like

Private Sub cmboSelectLicence_BeforeUpdate (Cancel as Integer)
If Dlookup("CountFieldNameHere","qryLicensesRemaining ","[LicenseIDFieldNameHere]=" & Me.cmboSelectLicense.Value) > 0 then
'do whatever is needed to add the licence
Else
Msgbox "Sorry, no workstation allocations are left for that licence. You may curse the system administrator now.", vbinformation
Cancel = True 
End if
End sub