Get sum of two columns in one LINQ query

Question

let\'s say that I have a table called Items (ID int, Done int, Total int)

I can do it by two queries:

int total = m.Items.Sum(p=>p.Total)
int done         


        

Answer 1

With a helper tuple class, either your own or—in .NET 4—the standard ones you can do this:

var init = Tuple.Create(0, 0);

var res = m.Items.Aggregate(init, (t,v) => Tuple.Create(t.Item1 + v.Total, t.Item2 + v.Done));

And res.Item1 is the total of the Total column and res.Item2 of the Done column.

Answer 2

//Calculate the total in list field values
//Use the header file: 

Using System.Linq;
int i = Total.Sum(G => G.First);

//By using LINQ to calculate the total in a list field,

var T = (from t in Total group t by Total into g select g.Sum(t => t.First)).ToList();

//Here Total is a List and First is the one of the integer field in list(Total)

Answer 3

To sum the table, group by a constant:

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)
}