Ms Access Vba Code Error Handling
Contents |
soon) Ruby (coming soon) Getting Started Code Samples Resources Patterns and Practices App Registration Tool Events Podcasts Training API Sandbox Videos Documentation Office Add-ins Office Add-in Availability Office Add-ins Changelog Microsoft Graph API Office 365 Connectors access 2010 vba error handling Office 365 REST APIs SharePoint Add-ins Office UI Fabric Submit to the Office Store vba error handling examples All Documentation https://www.yammer.com/ http://feeds.feedburner.com/office/fmNx How do I... Miscellaneous Maintenance Maintenance Handle Run-Time Errors in VBA Handle Run-Time Errors in VBA Handle ms access error handling best practice Run-Time Errors in VBA Compact and Repair a Database Recover Tables Deleted from a Database Handle Run-Time Errors in VBA TOC Collapse the table of content Expand the table of content This documentation is vba error handling best practices archived and is not being maintained. This documentation is archived and is not being maintained. Handle Run-Time Errors in VBA Office 2013 and later Other Versions Office 2010 Contribute to this content Use GitHub to suggest and submit changes. See our guidelines for contributing to VBA documentation. Errors and Error Handling When you are programming an application, you need to consider what happens when an error occurs. An error can
Access Vba Error Handling Module
occur in your application for one of two of reasons. First, some condition at the time the application is running makes otherwise valid code fail. For example, if your code attempts to open a table that the user has deleted, an error occurs. Second, your code may contain improper logic that prevents it from doing what you intended. For example, an error occurs if your code attempts to divide a value by zero. If you have not implemented error handling, Visual Basic halts execution and displays an error message when an error occurs in your code. The user of your application is likely to be confused and frustrated when this happens. You can forestall many problems by including thorough error-handling routines in your code to handle any error that may occur. When adding error handling to a procedure, you should consider how the procedure will route execution when an error occurs. The first step in routing execution to an error handler is to enable an error handler by including some form of the On Error statement within the procedure. The On Error statement directs execution in event of an error. If there is no On Error statement, Visual Basic simply halts execution and displays an error message w
a full version of Access, while a run-time version just crashes. For a more detailed approach to error handling, see FMS' article on Error Handling and Debugging.
Ms Access On Error Resume Next
The simplest approach is to display the Access error message and quit the error number : -2147217900 vba procedure. Each procedure, then, will have this format (without the line numbers): 1 Sub|Function SomeName() 2 On Error GoTo vba error handling display message Err_SomeName ' Initialize error handling. 3 ' Code to do something here. 4 Exit_SomeName: ' Label to resume after error. 5 Exit Sub|Function ' Exit before error handler. 6 Err_SomeName: ' Label https://msdn.microsoft.com/en-us/library/office/ff193267.aspx to jump to on error. 7 MsgBox Err.Number & Err.Description ' Place error handling here. 8 Resume Exit_SomeName ' Pick up again and quit. 9 End Sub|Function For a task where several things could go wrong, lines 7~8 will be replaced with more detail: Select Case Err.Number Case 9999 ' Whatever number you anticipate. Resume Next ' Use this to just ignore the line. Case http://allenbrowne.com/ser-23a.html 999 Resume Exit_SomeName ' Use this to give up on the proc. Case Else ' Any unexpected error. Call LogError(Err.Number, Err.Description, "SomeName()") Resume Exit_SomeName End Select The Case Else in this example calls a custom function to write the error details to a table. This allows you to review the details after the error has been cleared. The table might be named "tLogError" and consist of: Field Name Data Type Description ErrorLogID AutoNumber Primary Key. ErrNumber Number Long Integer. The Access-generated error number. ErrDescription Text Size=255. The Access-generated error message. ErrDate Date/Time System Date and Time of error. Default: =Now() CallingProc Text Name of procedure that called LogError() UserName Text Name of User. ShowUser Yes/No Whether error data was displayed in MsgBox Parameters Text 255. Optional. Any parameters you wish to record. Below is a procedure for writing to this table. It optionally allows recording the value of any variables/parameters at the time the error occurred. You can also opt to suppress the display of information about the error. Function LogError(ByVal lngErrNumber As Long, ByVal strErrDescription As String, _ strCallingProc As String, Optional vParameters, Optional bShowUser As Boolean = True) As Bo
Tools VBA Time Saver Kit โ code snippets & VBA reference VBA Web Scraping Kit โ easy scraping for Excel VBA Compiler (to VB.NET) VBA Multithreading Tool Excel Scrape HTML Add-In Documentation Google Charts Tool Excel SQL Add-In Excel Optimizer http://analystcave.com/vba-proper-vba-error-handling/ How to install Excel AddIns? VBA Questions? Contact Search for: Home ยป Proper VBA error handling Excel, MS Office, Outlook, PowerPoint, Word Proper VBA error handling (3 votes, average: 4.67 out of 5) Loading... October 22, 2015 AnalystCave Leave http://datagnostics.com/dtips/vbaerrors.html a comment Writing VBA code is hard, but properly debugging code is even harder. Sounds like non-sense? Well I dare say developers spend more time debugging code than writing it. Looking for errors is what developers do most error handling of the time! A critical part of debugging is proper error handling (VBA error handling in our case). Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it. โ Brian W. Kernighan However, today I don't want to expand on debugging VBA. That I covered in this post. No - today let's learn how vba error handling to properly handle errors The Mouse Trap Analogy What is error handling? Take this analogy: Say you have a mouse (an error) in the house which turns up every now and then in the least expected moment as slips from your hands (an uncaught exception if you prefer). Without knowing where the mouse is and when it (the exception/error) will appear (in which line of code) you would need to search entire house to catch it (run through the entire code in our case). Obviously a better approach is setting mouse traps in several critical places in the house (corridors etc.) and waiting for the mouse to fall into your trap. So what is our mouse trap when speaking about VBA error handling? The On Error do this statement! Using VBA On Error The VBA On Error statement - tells VBA what it should do from now on, within the vicinity of the current block of code (Function or Sub), when an error/exception is raised. It is like setting a mouse trap - with the difference that you can tell it to drop the mouse off the dumpster or put it in your hands to manage. Let's remind the full syntax of the On Error statement in VBA first: On Error { GoTo [ line | 0 ] | Resume Next } Directly from MSDN we learn the different VBA
error condition is raised. If you have made provision for that possibility, your code can recover gracefully and continue or terminate as appropriate; if not, Access will do its best to handle the error itself -- usually not in the way you would prefer. An untrapped, or unhandled, error is one that is raised by your application and not handled by error-handling code that you write. Such errors are then dealt with by Access's default error-handling routine, which displays the description of the error and, depending on your option settings, may allow you to debug the code. But it also tends to reset the VBA project, so that all global variables are returned to their uninitialized states. And if the database is run using the Access run-time module and not the full version of Access, the application will simply shut down. To avoid having this happen, put error-handling code in (at least) all your top-level VBA procedures. By "top-level" procedures, I mean those that are not called by other procedures you write, but rather are triggered by events. You can also write whatever specialized error-handling you want for lower-level procedures that are called from the top-level procedures, but if a lower-level procedure doesn't have its own error-handling code, its errors will be handled by a higher-level procedure's error-handler, if there is one, so you don't *necessarily* have to write an error-handler for every procedure. By error-handling code, I refer to using the On Error statement to define what will happen and where code execution will continue in the event of an error being raised by your code. Most often you will want to use the "On Error GoTo" form of the statement, to transfer control to an error-handling section in the procedure, from which section, eventually, the Resume statement is used to continue execution after the error has been dealt with. An alternative to this is "in-line" error-handling, which is done by using the "On Error Resume Next" statement. In that case, your own code checks after executing each statement, to see if an error has occurred, and deals with errors right there. Here's a very basic example of error-handling using "On Error GoTo", with comments on the essential elements: code: click in the frame, Select All, then Paste into your code editor Here's an ex