Question

I have a VB6 function, which executes an SQL delete. The function returns a boolean depending on whether or not the deletion was successful:

Public Function Delete(ByVal RecordID As Integer)  As Boolean

On Error GoTo ErrorGenerated //Execute SQL delete

Delete = True

Exit Function

ErrorGenerated: Delete = False

End Function

I read somewhere that it is better to return an integer, which dictates whether or not the deletion was successful. However, there can only be two outcomes from running the function from what I can see i.e. deleted or not deleted (not deleted if an error is thrown). Is it better to return an integer?

Answer 1

I’d suggest your best bet is to return an enumerated type; each value for the enumeration can then explain to the caller what the problem is in a clear and unambiguous way, and new error reasons can be added later as required without breaking anything. Something like…

Public Enum DB_ERRS
    Success
    NoConnection
    FailedForThisReason
    FailedForThatReason
    FailedForOtherReason
    Failed
End Enum

Then all your database access functions could return a value of this type…

Public Function Delete(ByVal RecordID As Integer) As DB_ERRS

  On Error GoTo ErrorGenerated
  Execute SQL delete
  Delete = Success
  Exit Function

  ErrorGenerated:

  If Err.Number = this Then
     Delete = FailedForThisReason
  Else
     Delete = Failed
  End If

End Function 

Intellisense will even help you fill them in.