To be fair (somewhat)...
The user control I'm using was not designed to be used by multiple
connections (users). Thus I suppose they see their in-memory copy as the
real golden data with the DB as a means to persist the data on disk.
The "polling" is somewhat unclear to me. I know that there is some sort of
5s polling by watching the file read and writes with Sysinternals FileMon.
Every 5s I see a read. After my process updates the database, I see that the
next read made by the UserControl process is followed by a file Flush and
other activity, presumably synchronizing their DataSet.
I believe this type of polling is built in functionality of OLE DB and
ADODB. When I create my ADODB connection I see another polling of the
database file with a period of 5s.
Any other thoughts are appreciated.
[quoted text, click to view] "Kerry Moorman" wrote:
> Terrence,
>
> If I had a user control that
>
> 1. Overwrote database changes
> 2. Polled an Access database for changes every 5 seconds
>
> the first thing I would do is throw the user control in the trash.
>
> Kerry Moorman
>
>
> "brinko99" wrote:
>
> > I am using a User Control that reads and writes data to an Access Database
> > using OLE DB classes (OleDbConnection...) I believe the control is storing
> > data locally in a DataSet which populates a DataGrid.
> >
> > My application is trying to read and write data to this same database
> > directly and I'm using a simple ADODB connection. The trouble is that when I
> > update the database the changes are not always reflected in the control's
> > local copy.
> >
> > It seems the OLE DB connection polls for changes to the DB at an interval of
> > ~5s. If I select a tab which contains the DataGrid within the ~5s the data
> > is out of sync. If I wait longer than ~5s after the DB update then
> > everything remains in sync.
> >
> > Ideally the user control would refresh its DataSet before displaying the tab
> > with the DataGrid. As it is it only uses the automatic synchronization
> > (polling). To make matters worse, when tab is changed the control overwrites
> > my changes to the DB with the contents of the DataGrid which it believes it
> > most up to date.
> >
> > My question, is there anything I might do to the DB that would force the
> > control to update? I have a feeling that this is a long shot...
> >
> > Thanks,
> >
> > Terrence
