Sum table values

Question

I have a table where I return the amounts paid per taxpayer monthly. But I need to create a subtotal field, adding up the values of each month. Very similar to the Fibonacci sequence. The problem is that I need to look up when the taxpayer made the payment. In this part I’m winding up.

The data I currently have:

How I need the data to return:

I tried something like:

 double a = 0;
        double AnoContribuinte = 0;

        for (int i = 0; i < 10; i++)
        {
            a = a + Contribuinte;
            i++;
            Console.WriteLine(a);
        }

Only then I limited it to i< 10, and in fact I need I to be equal to the amount of data that the table has.

But in this way he enters a loop infinite, for I will always have some value.

Answer 1

I see some problems in this code:

1. The code appears to be manipulated monetary values and using the type double, this does not give hit, you will have rounding problems.
2. Is increasing i twice, I can’t imagine why this is necessary.
3. The data being taken does not vary.

What you can help with is this:

var listaContribuintes = PegaContribuintes(); // este método traz os contribuintes de algum lugar
Decimal subTotal = 0;

foreach (var item in listaContribuintes) {
    subTotal += item.Contribuinte;
    item.SubTotal = subTotal;
} 

Code:

using static System.Console;
using System.Collections.Generic;
                    
public class Program {
    public static void Main() {
        //as primeiras linhas abaixo é o mesmo que seria o método PegaContribuintes que eu usei no exemplo da resposta
        var pessoas = new List<Pessoa> { 
            new Pessoa { Nome = "Elias Vieira1", Contribuinte = 31.87m },
            new Pessoa { Nome = "Elias Vieira2", Contribuinte = 32.87m },
            new Pessoa { Nome = "Elias Vieira3", Contribuinte = 33.87m },
            new Pessoa { Nome = "Elias Vieira4", Contribuinte = 34.87m }
        };
        decimal subTotal = 0;
        foreach (var item in pessoas) {
            subTotal += item.Contribuinte;
            item.SubTotal = subTotal;
            WriteLine($"Nome: {item.Nome}, Contribuição: {item.Contribuinte}, SubTotal: {item.SubTotal}");
        }
    }
}

public class Pessoa {
    public string Nome { get; set; }
    public decimal Contribuinte { get; set; }
    public decimal SubTotal { get; set; }
}

Behold working in the ideone. And in the .NET Fiddle. Also put on the Github for future reference. You have to adapt to your list, be as it is composed.

If you have more details I will update the reply.

Answer 2

So let’s assume the following model:

public class Pessoa
{
    public string Nome { get; set; }
    public double Contribuinte { get; set; }
    public double SubTotal { get; set; }
}

And we have the following list, in the example below is being statically loaded:

var pessoas = new List<Pessoa>();
pessoas.Add(new Pessoa { Nome = "Elias Vieira", Contribuinte = 31.87d });
pessoas.Add(new Pessoa { Nome = "Elias Vieira", Contribuinte = 31.87d });
pessoas.Add(new Pessoa { Nome = "Elias Vieira", Contribuinte = 31.87d });
pessoas.Add(new Pessoa { Nome = "Elias Vieira", Contribuinte = 31.87d });

You can browse as follows:

var subTotal = 0.0d;
foreach(var pessoa in pessoas)
{
    subTotal += pessoa.Contribuinte;
    pessoa.SubTotal = subTotal;
}

Answer 3

As a suggestion, I would let the database solve the problem, look at this article, very good, in English!

http://www.databasejournal.com/features/mssql/article.php/3112381/SQL-Server-Calculating-Running-Totals-Subtotals-and-Grand-Total-Without-a-Cursor.htm

I hope it helps!