How to Use OrderBy in linq for DataTable in asp.net

Question

I have two Data table Folder_table and folder_filter. Both the table has two columns FolderName and FolderDateTime . In the Folder_Table i have values like below

FolderName   FolderDateTime

Test1        29/3/2014
Test2        20/12/2014
Test3        4/2/2014
test5        9/6/2014

I am using the below coding to copy 2 rows from Folder_table to folder_filter

folder_filter = Folder_table.Rows.Cast<System.Data.DataRow>().Take(2).CopyToDataTable();

I want to order by descending in FolderDateTime column. how to do that. PLease help

Answer 1

If your field data type is DateTime then you can use:

var sortedTable = Folder_table.AsEnumerable()
                 .OrderBy(r => r.Field<DateTime>("FolderDateTime"))
                 .CopyToDataTable();

If your column type is string then first you have to parse these values to DateTime type object. Use DateTime.ParseExact with format d\M\yyyy like:

var sortedTable = Folder_table.AsEnumerable()
                 .OrderBy(r => DateTime.ParseExact(r.Field<string>("FolderDateTime"),
                                                    "d/M/yyyy", CultureInfo.InvariantCulture))
                 .CopyToDataTable();

You should see: LINQ to DataSet/ DataTable - MSDN