How do I select records and summary in one query?

Question

The scenario is like this:

name | val  
'aa' | 10
'bb' | 20
'cc' | 30
*********
sum  | 60

For now I just select all the records in simple LINQ query and invoke the enumerator (ToList())

Then I loop over the list and summarize the val column.

Is there a better way? LINQ selects all to a new typed object so I dont know how to add the additional data.

thanks.

Answer 1

Anonymous type cant allow value to be added or edited once its created. so instead of returning anonymous type, you can use your custom output class. Something like this

        public class ResClass
        {
            public string name;
            public int value;
        }

        public class OutClass
        {
             public int sum;
             public List<ResClass> lstData;
        }

        int sum=0;
        var outtt = objTT.Where(x => x.id == 1).Select(x =>
        {
            sum += x.value;
            return new ResClass { name =  x.name, value= x.value };

        }).ToList();

        OutClass outCls = new OutClass { sum = sum, lstData = outtt };