Microsoft KB Archive/153897

= FIX: MFC DAO or ODBC App Crashes on Exit =

Article ID: 153897

Article Last Modified on 12/1/2003

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APPLIES TO


 * Microsoft Visual C++ 4.0 Standard Edition
 * Microsoft Visual C++ 4.1 Subscription
 * Microsoft Visual C++ 4.2 Enterprise Edition
 * Microsoft Visual C++ 4.2 Professional Edition
 * Microsoft Data Access Components 2.5

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This article was previously published under Q153897



SYMPTOMS
An application intermittently crashes on exit and an error similar to the following appears:

caused an invalid page fault in

module KERNEL32.DLL at 0137:bff9a07c.

This behavior occurs when the application is using the MFC DAO classes, the MFC ODBC classes, or the ODBC API to access a database using the Jet Database Engine.



RESOLUTION
Call the LoadLibrary function on the Jet Engine as shown in the sample code below. This call needs to be done only once during execution of the program. To minimize any adverse affect on performance, call LoadLibrary only after the database has been opened. Do not call FreeLibrary for this DLL. The DLL will be automatically unloaded when the application exits.

This bug has been fixed in Jet 3.5 that is included with Visual C++ 5.0. If you are using the ODBC, you can simply use the newer ODBC driver that is available with Visual C++ 5.0. If you are using DAO, you need to build your application using Visual C++ 5.0 to use DAO 3.5. The earlier MFC classes use DAO/Jet 3.0 and do not recognize DAO 3.5.



STATUS
This bug has been fixed in Jet 3.5 that is included with Visual C++ 5.0.



MORE INFORMATION
This problem occurs only if a dialog resource is loaded. This includes applications that use CFormView-derived classes, such as CRecordView and CDaoRecordView, as well as dialog-based applications.

The following sample code shows the workaround for a default MFC AppWizard application using the MFC DAO classes. The call to LoadLibrary is added to the Open function of the CDaoRecordset-derived class named CMySet. Similar logic can be used for the MFC ODBC classes.

To fix the DAOEnrol sample, add the LoadLibrary call in the sample code below to the CDaoEnrolDoc::OnNewDocument function, before the call to the base class CDocument::OnNewDocument function.

To fix the Enroll tutorial, add the LoadLibrary call in the sample code below to the CEnrollDoc::GetDatabase function, after the call to m_database.Open.

Sample Code
void CMySet::Open(int nOpenType, LPCTSTR lpszSql, int nOptions) {      CDaoRecordset::Open(nOpenType, lpszSql, nOptions);

// Load the Jet Engine to ensure that it remains in memory // during the shutdown process. LoadLibrary( "MSJT3032.DLL" ); }

Keywords: kbbug kbfix kbinterop kbdatabase kbprogramming kbvc500fix kbprb KB153897

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