Error Trapping

See Also

You can use the On Error GoTo statement to trap errors and direct procedure flow to the location of error-handling statements within a procedure. For example, the following statement directs the flow to the ErrorHandler: label line:

On Error GoTo ErrorHandler

Be sure to give each error handler label in a procedure a unique name that will not conflict with any other element in the procedure, and make sure you append a colon to the name. Within the procedure, place the Exit Sub or Exit Function statement in front of the error handler label so that the procedure doesn't run the error-checking code if no error occurs.

Sub CausesAnError()
    ' Direct procedure flow.
    On Error GoTo ErrorHandler
    ' Raise division by zero error.
    Err.Raise 11
    Exit Sub

ErrorHandler:
    ' Display error information.
    MsgBox "Error number " & Err.Number & ": " & Err.Description
    ' Resume with statement following occurrence of error.
    Resume Next
End Sub

The Raise method of the Err object generates the specified error. The Number property of the Err object returns the number corresponding to the most recent run-time error; the Description property returns the corresponding message text for a given error.

Notes

• In versions 1.x and 2.0 of Microsoft Access, you might have used the Error statement to generate the error, the Err function to return the error number, and the Error function to return a description of the error. Existing error-handling code that relies on the Error statement and the Error function will continue to work. However, it's better to use the Err object and its properties and methods when writing new code.
  
  
• Versions 1.x and 2.0 of Microsoft Access returned only one error for all Automation, (formerly called OLE Automation) errors. The COM component application that generated the error now returns the same error information that you would receive if you were working in that application. You may need to rewrite existing error-handling code to handle new Automation errors properly.
  
  
• If you wish to return the descriptive string associated with a Microsoft Access error or a Data Access Objects (DAO) error, but the error has not actually occurred in your code, you can use the AccessError method to return the string.

For more information about setting error traps and writing error-handling statements, see Chapter 9, "Error Handling and Debugging," in the OPG9TBD. For information about how to obtain the OPG9TBD, click .