query - select specific columns from datatable in c# using linq




How do I get a distinct, ordered list of names from a DataTable using LINQ? (5)

I have a DataTable with a Name column. I want to generate a collection of the unique names ordered alphabetically. The following query ignores the order by clause.

var names =
    (from DataRow dr in dataTable.Rows
    orderby (string)dr["Name"]
    select (string)dr["Name"]).Distinct();

Why does the orderby not get enforced?


To abstract: all of the answers have something in common.

OrderBy needs to be the final operation.


To make it more readable and maintainable, you can also split it up into multiple LINQ statements.

  1. First, select your data into a new list, let's call it x1 , do a projection if desired
  2. Next, create a distinct list, from x1 into x2 , using whatever distinction you require
  3. Finally, create an ordered list, from x2 into x3 , sorting by whatever you desire

Try the following

var names = (from dr in dataTable.Rows
             select (string)dr["Name"]).Distinct().OrderBy(name => name);

this should work for what you need.


You can use something like that:

dataTable.Rows.Cast<DataRow>().GroupBy(g => g["Name"]).Select(s => s.First()).OrderBy(o => o["Name"]);

var sortedTable = (from results in resultTable.AsEnumerable()
select (string)results[attributeList]).Distinct().OrderBy(name => name);






.net-3.5