Kevin,

My form has two drop down lists. The first has a store no. When a store no. is selected, it calls the code to get a list of all the invoice numbers for that store and uses a 2nd table (InvoiceList) from the invoice business object to populate the drop down list of invoices. When I step through the code after selecting a store, the error "Missing Operand" occurs in the filldataset command. The correct value of the store number has been passed in.

Everything looks correct to me. The only thing odd I noticed stepping through is that in the mmBusinessStateChangeEventArgs method, the primary key value showed up as null. Doesn't the 2nd table use the same primary key as the default table or do I need to specify it separately? Would that cause this error?

Here is the code for the business object:

        /// <summary>
        /// Returns a dataset of each distinct invoice number by store number
        /// </summary>
        /// <returns>Dataset of distinct invoice numbers</returns>
        public DataSet GetUniqueInvoices(string storeNo)
        {
            //Get all invoice numbers if store number is *
            if (storeNo == "*")
            {
                this.FillDataSet(this.GetCurrentDataSet(), "SELECT DISTINCT InvoiceNo from Invoice", "InvoiceList");
            }
            else
            {
                IDataParameter @StoreNo = this.CreateParameter("@StoreNo", storeNo);
                this.FillDataSet(this.GetCurrentDataSet(), "SELECT InvoiceNo FROM Invoice WHERE StoreNo = @StoreNo",
                    "InvoiceList");
            }
            return this.GetCurrentDataSet();
        }

Here is the complete stack trace:

   at System.Data.OleDb.OleDbCommand.ExecuteCommandTextForSingleResult(tagDBPARAMS dbParams, Object& executeResult)
   at System.Data.OleDb.OleDbCommand.ExecuteCommandText(Object& executeResult)
   at System.Data.OleDb.OleDbCommand.ExecuteCommand(CommandBehavior behavior, Object& executeResult)
   at System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method)
   at System.Data.OleDb.OleDbCommand.ExecuteReader(CommandBehavior behavior)
   at System.Data.OleDb.OleDbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior)
   at System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
   at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
   at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, String srcTable)
   at OakLeaf.MM.Main.Data.mmDataAccessOleDb.FillDataSet(DataSet ds, IDbDataAdapter dbAdapter, String tableName, Boolean clearOnFill)
   at OakLeaf.MM.Main.Data.mmDataAccessOleDb.FillDataSet(DataSet ds, IDbCommand command, String tableName, Boolean clearOnFill)
   at OakLeaf.MM.Main.Data.mmDataAccessOleDb.FillDataSet(DataSet ds, String command, String tableName, CommandType cmdType, IDbDataParameter[] dataParms, Boolean clearOnFill)
   at OakLeaf.MM.Main.Business.mmBusinessObject.FillDataSet(DataSet ds, String command, String tableName, String databaseKey, CommandType cmdType, IDbDataParameter[] dataParams)
   at OakLeaf.MM.Main.Business.mmBusinessObject.FillDataSet(DataSet ds, String command, String tableName, String databaseKey, IDbDataParameter[] dataParams)
   at OakLeaf.MM.Main.Business.mmBusinessObject.FillDataSet(DataSet ds, String command, String tableName, String databaseKey)
   at OakLeaf.MM.Main.Business.mmBusinessObject.FillDataSet(DataSet ds, String command, String tableName)
   at ESK.DataUploadSystem.Business.Invoice.GetUniqueInvoices(String storeNo) in C:\deve\ESK Invoice Upload System Business\Invoice.cs:line 116
   at ESK.InvoiceUploadSystem.Windows.ViewInvoices.ddlStoreNo_SelectedIndexChanged(Object sender, EventArgs e) in C:\deve\ESK Invoice Upload System Windows\ViewInvoices.cs:line 47
   at System.Windows.Forms.ComboBox.OnSelectedIndexChanged(EventArgs e)
   at System.Windows.Forms.ComboBox.WmReflectCommand(Message& m)
   at System.Windows.Forms.ComboBox.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.SendMessage(HandleRef hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   at System.Windows.Forms.Control.SendMessage(Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.Control.ReflectMessageInternal(IntPtr hWnd, Message& m)
   at System.Windows.Forms.Control.WmCommand(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at System.Windows.Forms.ContainerControl.WndProc(Message& m)
   at System.Windows.Forms.Form.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.CallWindowProc(IntPtr wndProc, IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   at System.Windows.Forms.NativeWindow.DefWndProc(Message& m)
   at System.Windows.Forms.Control.DefWndProc(Message& m)
   at System.Windows.Forms.Control.WmCommand(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ComboBox.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.Run(Form mainForm)
   at ESK.InvoiceUploadSystem.Windows.Main.AppMainEntry.Main() in C:\deve\ESK Invoice Upload System Windows\Main.cs:line 45

Thanks for any help you can offer.

Linda