Delphi DBGrid PickList通过sql查询语句中ltrim不显示下拉列表的问题

注意查询语句的字段中不能有ltrim(字段名) as (字段名) 否则该字段在DBGrid中不会显示下拉PickList列表

procedure TForm1.FormShow(Sender: TObject);
begin
   with dm.ADOQuery1 do
   begin
     dm.ADOQuery1.Close;
     dm.ADOQuery1.SQL.Clear;
     dm.ADOQuery1.SQL.Add('select * from xue');
     dm.ADOQuery1.Open;
   end;
   while not (dm.ADOQuery1.Eof) do
   begin
    dbgrid1.Columns[index].PickList.AddObject(dm.ADOQuery1.Fields[0].AsString);
    next;
   end;
end;