Order,group and sum List of array in ExpandoObject c#

Question

I am trying to sum the "col3" values by ordering and grouping the "col1" and "col2" using C# Linq.

    List<dynamic> list = new List<dynamic>();

    dynamic expando = new ExpandoObject();
dynamic expando1 = new ExpandoObject();

    var p = expando as IDictionary<string, object>;

    p["col1"] = "New val 1";
    p["col2"] = "New val 2";
    p["col3"] = 20;

    list.Add(p);

    var q = expando1 as IDictionary<string, object>;

    q["col1"] = "New val 1";
    q["col2"] = "New val 3";
    q["col3"] = 10;

    list.Add(q);

I am trying to get the output as

New val 1

New val 2

New val 3

Total -- 30

I am new to linq. Could find the right query to get my result. — Vasanthkumar Porcheziyan, Oct 19 '17 at 13:25
Please show what you have tried. Also your desired output isn't very clear. Please explain — Gilad Green, Oct 19 '17 at 13:26
You are using the same `ExpandoObject` twice. You are overwriting its values. — Dennis_E, Oct 19 '17 at 13:27
i am trying to group "col1" followed by "col2" and sum the "col3" value as my result — Vasanthkumar Porcheziyan, Oct 19 '17 at 13:42
Your list has a reference to the same object twice. That's the very first thing for you to understand. — Jon Skeet, Oct 19 '17 at 13:43
`p` and `q` refer to the same `ExpandoObject`. Try `Console.WriteLine(p["col3"]);` It will print 10, not 20. — Dennis_E, Oct 19 '17 at 13:44
Thanks for correcting me. I added new line of code. How i suppose to sum the "col3" by Grouping the "col1" and "col2" ? I am new to linq and ExpandoObject. — Vasanthkumar Porcheziyan, Oct 19 '17 at 14:10
What have you tried? What is the problem? Do you wan to group by both columns? Then the total will not be 30.. but for one group 10 and the other 20 — Gilad Green, Oct 19 '17 at 14:13
Giland:- I tried in linq lambda query. I can't figure a proper linq query for my scenario. Both the sets have common key "col1", "col2", "col3". I need to order the records based on these columns and Group these columns. Finally i need my result to be 30. How i suppose to achieve it? — Vasanthkumar Porcheziyan, Oct 19 '17 at 14:21
You need to edit your question to have a lot more sample data and show the results as objects, not as pretty pictures that don't mean anything in programming. — NetMage, Oct 19 '17 at 19:27

score 0 · Accepted Answer · answered Oct 20 '17 at 16:20

What is the reason of creating ExpandoObject, but using it like a dictionary? If you know the set of the properties (col1, col2, col3) it would be better to create separate class for it, otherwise it could be done like this.

var list = new List<dynamic>();
dynamic e1 = new ExpandoObject();
e1.col1 = "New val 1";
e1.col2 = "New val 2";
e1.col3 = 20;
list.Add(e1);

dynamic e2 = new ExpandoObject();
e2.col1 = "New val 1";
e2.col2 = "New val 3";
e2.col3 = 10;
list.Add(e2);

foreach (var group in list
    .OrderBy(e => e.col1)
    .GroupBy(o => o.col1))
{
    Debug.WriteLine((string)group.Key);
    var sum = 0;
    foreach (var item in group)
    {
        Debug.WriteLine("    " + (string)item.col2);
        sum += item.col3;
    }

    Debug.WriteLine("Total: " + sum);
}

Order,group and sum List of array in ExpandoObject c#

1 Answers1