Get sum of two columns in one LINQ query

This will do the trick:

LINQ Query Syntax:

from p in m.Items
group p by 1 into g
select new
{
    SumTotal = g.Sum(x => x.Total), 
    SumDone = g.Sum(x => x.Done) 
};

LINQ Method Syntax:

m.Items
 .GroupBy(r => 1)
 .Select(g => new 
 {
     SumTotal = g.Sum(x => x.Total), 
     SumDone = g.Sum(x => x.Done) 
 });

Notice that this solution (both syntax) returns a list of 1 item, so you might want to add at the end:

 .FirstOrDefault();