Microsoft Access 2010 Bible

Part III: More-Advanced Access Techniques

838

‘Insert your code here

ExitHere:

Exit Sub

HandleError:

If cnn.Errors.Count > 0 Then

If Err.Number = cnn.Errors.Item(0).Number Then

‘Error is an ADO Connection Error:

For Each errX In cnn.Errors

‘Loop through the Errors collection, displaying

‘the description of each Err object:

strMessage = strMessage & Err.Description & vbCrLf

Next errX

MsgBox strMessage, , “ADO Error Handler”

End If

Resume ExitHere

Else

‘The error is a VBA Error:

MsgBox Err.Description, vbExclamation, _

“VBA Error Handler”

Resume ExitHere

End If

End Sub

Summary

This chapter surveys the important topic of adding error handling in Access applications. All VBA

hosts (Access, Word, Excel, and so on) use identical error-handling paradigms. This means that all

the code you saw in this chapter is applicable to any VBA host application.

Error handling is enabled with the On Error keywords. The typical error-handling process is to

trap the error, redirect program execution to the code segment handling the error, and then

resume out of the error handler. Most procedures use the Resume statement to redirect program

flow to a common exit point in the procedure. The code following the exit label performs any

cleanup (closing and discarding object variables, closing files that are open, and so on) and is exe-

cuted regardless of whether an error occurs in the procedure.