Increment Number

[astroshark]

I am relatively new to the C# scene so I am a lot of rough around the edges. Anyways I am trying to pull a number value from an Access DB starting at 8000 and increment that value by one every time a user enters a new row into the Access DB, and then get that number to reset daily back to 8000. Also having that incremented number show up in a textbox once the user has pushed the data into the Access DB. I have a rough draft of some code, but of course, I have no clue if I am even starting off in the right direction. I am assuming most of the what I need will have to be based on the query of the OleDbConnection.

        protected void GetSerialNumber()
        {
            OleDbConnection db = new OleDbConnection(dbstr);
//Here is where I can't get a fix on writing a proper query to get the last number from the Access DB and increment it.
            string query = ;
            try
            {
                db.Open();
 
                try
                {
                    OleDbCommand command = new OleDbCommand();
                    command.CommandText = query;
                    command.Connection = db;
                    command.ExecuteNonQuery();
                }
                catch (Exception e)
                {
                    MessageBox.Show(e.Message);
                }
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message);
            }
            finally
            {
                db.Close();
            }
        }
 

I don't have any code to reset that number daily or being able to show the incremented number after the user has submitted the data into the DB, as I don't even know where to even begin on that part of the code. Any help on this would be greatly appreciated.