“Object Invalid or no Longer Set” when using Variable to Reference Collection

Question

In the process of answering this question, I wrote a simple function to test whether an MS Access table contained all fields in a supplied array:

Answer 1

The problem here is:

CurrentDb creates a DAO.Database object of the currently open database. Your TableDef is a member of that.

But since you're not storing that object, it gets closed and deallocated right after you copied the tabledef to an object, and with it the members will be deallocated too.

Store the database object, and the members will also persist:

Function ValidateFields(strTbl As String, arrReq As Variant) As Boolean
    Dim fld
    Dim fldTmp As Field
    Dim colFld As Fields
    Dim db As DAO.Database
    Set db = CurrentDb
    Set colFld = db.TableDefs(strTbl).Fields
    On Error GoTo err
    For Each fld In arrReq
        Set fldTmp = colFld(fld)
    Next fld
    ValidateFields = True
err:
    Exit Function
End Function