cannot perform this operation on a closed dataset问题
我的系统若开始先点查询,就可以查到单据表里的所有内容,系统正常运行.但是如果我先执行了单据表的结账模块,之后再进入查询,当点击查询按钮时就会出现cannot perform this operation on a closed dataset!
我用单步执行时过程如下:(先执行结账模块之后,进入单据查询窗体...
我的查询模块：
procedure TfrmSearchInfo.BitBtn3Click(Sender: TObject);
begin
DM.qryOrderDishes.Close; //单据表 <----------------------------------------------单步执行开始跳转位置
DM.qryOrderDishes.SQL.Clear;
DM.qryOrderDishes.SQL.Add('SELECT * FROM OrderDishes');//查询所有
DM.qryOrderDishes.SQL.Add('WHERE 0=0');
if edtOrderDishesID.Text <> '' then
DM.qryOrderDishes.SQL.Add(' AND OrderDishesID LIKE ' + QuotedStr('%'+ edtOrderDishesID.Text +'%'));
if edtDiningTableID.Text <> '' then
DM.qryOrderDishes.SQL.Add(' AND DiningTableID LIKE ' + QuotedStr('%'+ edtDiningTableID.Text +'%'));
if edtCustomer.Text <> '' then
DM.qryOrderDishes.SQL.Add(' AND Customer LIKE ' + QuotedStr('%'+ edtCustomer.Text +'%'));
DM.qryOrderDishes.Open;
DM.qryOrderDishes.First;
end;

我的结账模块中当输入用餐金额计算折扣金额的代码:
procedure TfrmDiningBalance.edtTotalsMoenyChange(Sender: TObject);
begin <-----------------------------单步执行跳转到这里!
DM.qryVIP.Close; //会员表
DM.qryVIP.SQL.Clear;
DM.qryVIP.SQL.Add('SELECT * FROM VIP');
DM.qryVIP.SQL.Add('WHERE 0=0');
DM.qryVIP.Open;
DM.qryOrderDishes.Edit ; //单据表编辑<---------------------------单步执行到这里后出现错误信息
if edtTotalsMoeny.Text <> '' then //当输入用餐金额不为空时
DM.qryOrderDishes.FieldByName('RebateMoney').AsString := FloatToStrStrToFloatedtTotalsMoeny.Text) * DM.qryVIP.FieldByName('Discount1').AsFloat);
//执行折扣金额=用餐金额*折扣率(会员表内容)
end;
感觉像是执行到edit,但查询窗口不允许执行edit操作,所以提示出错.但是为什么程序会发生这样的跳转? 请大虾们不吝赐教!万分感谢!

[解决办法]
qryOrderDishes已经被关闭,所以Edit要出错,至于在哪里被关闭,查查代码吧
[解决办法]
DM.qryOrderDishes没有打开