DOCUMENT:Q145719  03-AUG-2001  [visualc]
TITLE   :BUG: DAOENROL - Can't See Added Records in Windows 95
PRODUCT :Microsoft C Compiler
PROD/VER:winnt:4.0,4.1; :
OPER/SYS:
KEYWORDS:kbother kbDAOsearch kbDatabase kbMFC kbVC

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The information in this article applies to:

 - Microsoft Visual C++, versions 4.0, 4.1 
 - Microsoft Foundation Classes (MFC) 
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SYMPTOMS
========

If you run the DAOENROL sample from Visual C++ version 4.0, 4.1, or 4.2 under
Windows 95 and you add a record, you may not see the record in the result set.
If you exit the program, restart it and scroll through the records. You will
then see the added record. The "More Information" section below gives a more
detailed scenario that shows the problem.

CAUSE
=====

The CDaoRecordView class keeps track of the first and last record by using
Microsoft Jet bookmarks. Microsoft Jet bookmarks should not be assumed to be
valid following a Requery(). DAOENROL does a Requery() following an add and a
move, but it continues to use the bookmark values it obtained before the
Requery() was done.

RESOLUTION
==========

To fix the DAOENROL sample, you must re-initialize the CDaoRecordView bookmark
members following a Requery(). DAOENROL performs a Requery() in three places:

 - in the CAddForm::OnMove() function in Addform.cpp.

 - in the CSectionForm::OnSelendokCourselist() function in Sectform.cpp.

 - in the CSectionForm::OnMove() function in SectForm.cpp.

In each of these locations, you should add code similar to this:

      m_pSet->Requery();           // here's the existing Requery()

      m_varBookmarkCurrent = 1L;   // add these...
      m_varBookmarkFirst =         // ...lines of...
         m_varBookmarkLast = 0L;   // ..code!

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. We are researching this problem and will post new
information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION
================

Steps to Reproduce Problem
--------------------------

1. Run the DAOENROL sample on Windows 95.

2. Click the Next button to move to the last record.

3. Click the Plus button to add a record.

4. Type a 3 in all blank fields of the new record.

5. Click the Previous button to move off the new record.

6. Click the Next button to scroll through the result set. You will not see the
   record you just added.

NOTE: If you run DAOENROL under Windows NT, you will see the added record.
Although the problem is masked in Windows NT, the behavior of bookmarks after a
Requery() is undefined and may change in future releases of either operating
system. Any behavior exhibited should not be relied on.

REFERENCES
==========

For more information, please see the following article in the Microsoft
Knowledge Base:

   Q145686 PRB: CDaoRecordView Bookmark Members Invalid After Requery()

Additional query words: kbVC400bug

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Keywords          : kbother kbDAOsearch kbDatabase kbMFC kbVC 
Technology        : kbVCsearch kbVC400 kbAudDeveloper kbMFC kbVC410
Version           : winnt:4.0,4.1; :
Issue type        : kbbug

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Copyright Microsoft Corporation 2001.