Question

I have following two calls, both are same but results are different…

It is simple console application with connection to local database.

DBContext db = new DBContext();

This one sorts as expected,

var q = from x in db.Cities
        orderby x.CountryCode, x.City
        select x;

foreach(var x in q){
   Console.WriteLine("{0}:{1}",x.CountryCode, x.City);
}

But why this one does not sort by City, it only sorts by CountryCode

foreach(var x in db.Cities.OrderBy(d=>d.City).OrderBy(d=>d.CountryCode)){
   Console.WriteLine("{0}:{1}",x.CountryCode, x.City);
}

If I change order of OrderBy statements, then only Last OrderBy seem to work correctly but intermediate OrderBy has no impact at all. Is this bug in EF or Linq extensions?

I have no problem in rewriting queries but I want to know what is wrong with OrderBy Linq Extension method?

Answer 1

I have a blog post about this: http://www.kristofclaes.be/blog/2010/07/06/order-on-multiple-fields-with-linq/

The problem is that the second OrderBy() overrules the first one. To fix this, you can replace the second OrderBy() with ThenBy() like this:

db.Cities.OrderBy(d=>d.City).ThenBy(d=>d.CountryCode)