In VBA how do I now when a Database variable has not been initialised?

Question

My idea was this, I declare the object, and set it once...

Private dbLeghe As Database

Public Sub OpenLegaDb()
    ' Only open the database if it has not already been done
    If dbLeghe Is Nothing Then
        Set dbLeghe = OpenDatabase("C:\PrevColl\Solder.mdb", , True)
    End If
End Sub

...but I don't understand how to check if it dbLeghe has been set or not. Is Nothing does not seem to work...

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http://www.ransen.com Cad and Graphics software

Answer 1

Hi,

Is Nothing should work. Why do you say it does not seem to work? How exactly are you verifying if it's working or not?

Looking at your code, I imagine the If statement is always True, correct? If so, are you saying dbLeghe still does not get set even after the Set line? If you say yes, then perhaps the issue is in the use of the Private scope for the variable.

Just my 2 cents...

Answer 2

the "standard" version of this supports .DBguys analysis. But the question is how to access that database after it's initialized?

This should work

Option Compare Database
Option Explicit


Private m_db As DAO.Database

Public Property Get CurrentDbC() As DAO.Database

    If (m_db Is Nothing) Then
        Set m_db = CurrentDb
    End If
    
    Set CurrentDbC = m_db

End Property

which I attribute to Dirk Goldgar

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peter n roth - http://PNR1.com, Maybe some useful stuff

Answer 3

Looking at your code, I imagine the If statement is always True, correct? If so, are you saying dbLeghe still does not get set even after the Set line? If you say yes, then perhaps the issue is in the use of the Private scope for the variable.

Just my 2 cents...

No, the if statement is not always true, because after the first time that I call OpenLegDb it dbLeghe has been set to something, i.e. not Nothing.

But the error was mine, I ported from a locally opened db to a globally opened one, but forgot to remove the .Close in one of the ported functions. Arrrg!

Sorry to have wasted your time everyone!

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http://www.ransen.com Cad and Graphics software

Answer 4

Hi Owen,

Glad to hear you got it sorted out. Good luck with your project.