在一个ComboBox中定义如下语句
//给员工列表赋值
DataMDP->Query2->Close();
DataMDP->Query2->UnPrepare();
DataMDP->Query2->SQL->Clear();
DataMDP->Query2->SQL->Add("select clerk_code,clerk_name from clerk where depart_code=:depart_code order by clerk_code");
DataMDP->Query2->ParamByName("depart_code")->AsString =DepartCodeCB->Text.SubString(1,5);
DataMDP->Query2->Open();
DataMDP->Query2->First();
ClerkCodeCB->Clear();
while(!DataMDP->Query2->Eof)
   {
   ClerkCodeCB->Items->Add(DataMDP->Query2->FieldByName("clerk_code")->AsString+"_"+
                             DataMDP->Query2->FieldByName("clerk_name")->AsString);
   DataMDP->Query2->Next();
   }
DataMDP->Query2->Active = false;
ClerkCodeCB->ItemIndex=0;
//给部门领导审批人列表赋值
  DataMDP->Query2->Close();
  DataMDP->Query2->UnPrepare();
  DataMDP->Query2->SQL->Clear();
  DataMDP->Query2->SQL->Add("select clerk_code,clerk_name from clerk where depart_code=:depart_code and clerk_class between '2' and '3' order by clerk_code");
  DataMDP->Query2->ParamByName("depart_code")->AsString =DepartCodeCB->Text.SubString(1,5);
  DataMDP->Query2->Open();
  DataMDP->Query2->First();
  ComboBox11->Clear();
  while(!DataMDP->Query2->Eof)
   {
   ComboBox11->Items->Add(DataMDP->Query2->FieldByName("clerk_code")->AsString+"_"+
                             DataMDP->Query2->FieldByName("clerk_name")->AsString);
   DataMDP->Query2->Next();
   }
  DataMDP->Query2->Active = false;
  ComboBox11->ItemIndex=0;

//重新计算部门预算各项指标值
TakeYs(Sender);
ClerkCodeCBChange(Sender);

在的有的客户端执行的时候就会报"cursor handle  ..."出错,这是为何?