The safest bet is to assume you can’t detect and handle every unexpected circumstance and that exceptions will inevitably occur. When an exception occurs, you should follow a standard series of steps—basic do’s and don’ts—to handle the exception. Here is what your system should and shouldn’t do when designing your application to cope with exceptions:
DO write Try...Catch or On Error GoTo exception handling on all database interactions. Pay special attention to where the database is being accessed for the first time—because if there is a network outage or a bad file path to the database, this is where it will be first detected.
DO report an error to the user explaining briefly what went wrong and what she should do next. Examples ...