至少一个参数没有指定值


这行  至少一个参数没有指定值 thisAdapter.Fill(thisDataset, "Customers");什么意思啊 
编译没有错  执行才报错
 OleDbConnection thisconnection = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source =D:\aaa\Nwind2.mdb");
            thisconnection.Open();
 OleDbDataAdapter thisAdapter = new OleDbDataAdapter("SELECT CustomerID,CompanyName from Customers", thisconnection);
            OleDbCommandBuilder thisbuilder = new OleDbCommandBuilder(thisAdapter);
            DataSet thisDataset = new DataSet();
            thisAdapter.Fill(thisDataset, "Customers");
            Console.WriteLine("name before changed:{0}",thisDataset.Tables["Customers"].Rows[9]["CompanyName"]);
           
            thisDataset.Tables["Customers"].Rows[9]["CompanyName"] = "Acnc,3D";
            thisAdapter.Update(thisDataset, "Customers");
            Console.WriteLine("name after changed:{0}",thisDataset.Tables["Customers"].Rows[9]["CompanyName"]);
                      
            thisconnection.Close();
            Console.WriteLine("Program finished,press Enter/Rerturn to continue:");
            Console.ReadLine();