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Child Windows Freeze on large SQL query

I have a C++ MDI application using MFC with SQLServer. The sql query is complex and takes approximately 20 sec to complete. This freezes the application and the user can't do any thing in the other child windows. I would like to know what should be done to allow the user to continue on the other Child windows while the sql query retrieves its information.

A snip of my code:

CDatabase m_db;

Interface::Interface()
{
      m_db.OpenEx("DSN=MYsql;Description=test;APP=Microsoft\x00ae Visual Studio .NET;WSID=TEST;DATABASE=myDB;Trusted_Connection=Yes");
}

CMyRecView.h
-----------------
class CMyRecView : public CRecordView
{
protected:
      CMyRecView();
..
..
}

CMyRecView.cpp
-----------------
void CMyRecView::OnBnClickedRequest()
{

      CDynamicBulkSet rs(&m_db);
      rs.Open(CRecordset::snapshot, "SELECT * FROM tblLeaders", CRecordset::readOnly | CRecordset::useMultiRowFetch);

      FillGrid(&rs);
      rs.Close();
}

Many Thanks,
Dan

Roshan Davis

I think the problem is not in the query, the function FillGrid will take much amount of time for a bulk data, so the messages will block add this snippet in that function (in the loop of that function)

void CYourClass::FillGrid(CRecordset& rs)
{
      MSG msg;

      (******* LOOP *******)
      {

            while ( ::PeekMessage(&msg, NULL, NULL, NULL, PM_REMOVE) )
            {
                  ::TranslateMessage(&msg);
                  ::DispatchMessage(&msg);
            }

            m_wndYourList.InsertItem(.........);

      }

Good LUck

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itsmeandnobodyelse

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DBOTMA

ASKER

The problem is not with FillGrid, even with the line commented out it still take 20 seconds.

Please note: The sql "select * from tblLeaders" is only to show the problem.

Any better solutions than using a worker thread?