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

Solution 1:

The problem is that the Distinct operator does not grant that it will maintain the original order of values.

So your query will need to work like this

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

Solution 2:

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