Narrowing LINQ query to one column

I'm trying to setup a query like this. So at first I'm selecting complete objects..

var values = (from p in Products
              where p.LockedSince == null
              select p);

Then optionally I'm adding extra where's

if(SupplierId > 0)
    values = values.Where(p => p.SupplierId == SupplierId);

And in 开发者_如何学运维the end, I don't need the complete product objects anymore, I just need a simple distinct and ordered list of one column (p.LocationName) .. something like this:

values = values.Select( p.LocationName ).Distinct().OrderBy(x => x);

I've tried something like Select(loc => new { p.LocationName }), but with no luck.

If you don't need intermediate results more effective way would be to write single query

var values = (from p in Products 
              where (p.LockedSince == null && (SupplierId <=0 || p.SupplierId == SupplierId))
              select p.LocationName).Distinct().OrderBy(x => x);

values = values.Select( p => p.LocationName ).Distinct().OrderBy(x => x);