SPQuery query = new SPQuery();
query.Query = @"<OrderBy><FieldRef Name ='LinkOrder'></FieldRef></OrderBy>";
SPList list_MainList = ssweb.Lists.TryGetList(PosMainList);
SPListItemCollection mainCollection = list_MainList.GetItems(query);
List<string> list_mainCollection = mainCollection.Cast<SPListItem>().OrderBy(x => x.ToStringExtension("LinkOrder")).Select(x => x.ToStringExtension("InternalFieldName")).ToList();
List<string> fields = new List<string>();
fields.AddRange(list_mainCollection);
SPListItemCollection items = ssweb.Lists.TryGetList(listName).GetItems(fields.ToArray());
var records = items.GetDataTable().AsEnumerable();
records = records.Where(x => DateTime.Parse(x.Field<string>("Year") + "-" + x.Field<string>("Month")) <= DateTime.Parse(strs[0] + "-" + strs[1]));
DataView dv = records.AsDataView();
return records.AsDataView().ToTable();