PRB: CDaoRecordView Bookmark Members Invalid After Requery() (145686)
The information in this article applies to:
- The Microsoft Foundation Classes (MFC), when used with:
- Microsoft Visual C++, 32-bit Enterprise Edition 4.2
- Microsoft Visual C++, 32-bit Enterprise Edition 4.2b
- Microsoft Visual C++, 32-bit Enterprise Edition 5.0
- Microsoft Visual C++, 32-bit Enterprise Edition 6.0
- Microsoft Visual C++, 32-bit Professional Edition 4.0
- Microsoft Visual C++, 32-bit Professional Edition 4.1
- Microsoft Visual C++, 32-bit Professional Edition 4.2
- Microsoft Visual C++, 32-bit Professional Edition 4.2b
- Microsoft Visual C++, 32-bit Professional Edition 5.0
- Microsoft Visual C++, 32-bit Professional Edition 6.0
- Microsoft Visual C++, 32-bit Learning Edition 4.0
- Microsoft Visual C++, 32-bit Learning Edition 4.2
- Microsoft Visual C++, 32-bit Learning Edition 4.2b
- Microsoft Visual C++, 32-bit Learning Edition 6.0
This article was previously published under Q145686 SYMPTOMS
In some cases, when you use CDaoRecordView, added records will not show up
in the result set after calling Requery() on the CDaoRecordset.
CAUSE
CDaoRecordView uses Jet engine bookmarks to determine when you are on
the first or last record of the related CDaoRecordset. Jet engine
bookmarks are not guaranteed to be valid following a Requery().
RESOLUTION
To avoid the problem, re-initialize the CDaoRecordView bookmark members to
indicate that they are not valid bookmark values following any Requery() on
the related CDaoRecordset. The following example shows how this might be
done in a CDaoRecordView-derived class's OnMove() function:
BOOL CMyRecordView::OnMove(UINT nIDMoveCommand)
{
CDaoRecordset* pRecordset = OnGetRecordset();
if (m_bAddMode)
{
if (!UpdateData())
return FALSE;
try
{
pRecordset->Update();
}
catch (CDaoException* e)
{
AfxMessageBox(e->m_pErrorInfo->m_strDescription);
e->Delete();
return FALSE;
}
pRecordset->Requery();
m_varBookmarkCurrent = 1L; // <<- re-initialize
m_varBookmarkFirst = // <<- the bookmark
m_varBookmarkLast = 0L; // <<- member variables!
UpdateData(FALSE);
m_bAddMode = FALSE;
return TRUE;
}
else
{
return CDaoRecordView::OnMove(nIDMoveCommand);
}
}
If you call Requery() in any other case from your CDaoRecordView-derived
class, you should also perform this re-initialization.
STATUS
This behavior is by design.
| Modification Type: | Major | Last Reviewed: | 12/9/2003 |
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| Keywords: | kbDatabase kbprb kbusage KB145686 |
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