CODEWITHSUNDEEP
c#linqlambdalinq-expressions
user3032509
user3032509

Reputation: 73

.Sum() in lambda expressions

I'm new to lambda expressions. I'm trying to use the .Sum() method to a result from a db search, I want to sum all the values from the Importe column, I'm selecting the values using an ID from another table, but the Json send me back the entire list with every value, it's not doing the sum. Or maybe I don't know how to apply it?

Thank you

public JsonResult IngresaCuentas(string codigo)
{
    ContextoAngeles db = new ContextoAngeles();

    var suma = (from data in db.Cuentas
                where data.Codigo == codigo
                select (from n in db.MovimientosPolizas
                        where data.Id == n.IdCuenta
                        group n by new { n.Importe} into g
                        let sumaTotal = (g.Sum(n => n.Importe))
                        select new
                        {
                            Total: sumaTotal
                        })).ToList();

        return Json(suma, JsonRequestBehavior.AllowGet);
}

I'm getting this in the Console:

[[{"Total":0},{"Total":20},{"Total":150},{"Total":330},{"Total":56.2},{"Total":240},{"Total":1750},{"Total":70.07},{"Total":480},{"Total":540},{"Total":95},{"Total":200},{"Total":108},{"Total":108.8},{"Total":880},{"Total":111.98},{"Total":115},{"Total":240},{"Total":125},{"Total":129.98},{"Total":780},{"Total":131.42},{"Total":134.59},{"Total":1260},{"Total":141.65},{"Total":145}]] (and a lot more..)

Upvotes: 2

Views: 33151

Answers (2)

user3032509
user3032509

Reputation: 73

A friend helped me to resolve this issue and a Join was the answer. I think i didn't explain my problem clear enough, I was trying to do that but in a different way more like SQL syntax, if anyone knows a good place to learn about lambda expressions would be great.

Thank all of you! Here the solution.

 var dato = db.Cuentas.Where(x => x.Codigo == codigo)
                .Join(db.MovimientosPolizas, cuentas => cuentas.Id, movimientos => movimientos.IdCuenta, (cuenta, movimiento) => new { sumImporte = movimiento.Importe, cuenta = cuenta.Nombre })
                .Sum(x => x.sumImporte);

Upvotes: 3

Corey Adler
Corey Adler

Reputation: 16137

When you are using select new { Total: sumaTotal }, that's not just sending back the int, that's sending you an object of an anonymous type with a Total field. I don't think that that's what you're going after.

What I think you should be doing is something like this:

var suma = (from data in db.Cuentas
            where data.Codigo == codigo
            select (from n in db.MovimientosPolizas
                    where data.Id == n.IdCuenta
                    group n by new { n.Importe} into g
                    let sumaTotal = (g.Sum(n => n.Importe))
                    select sumaTotal)).ToList();

Or, if what you're going for is to select the sum of every Importe that you've queried:

var suma = (from data in db.Cuentas
            where data.Codigo == codigo
            select (from n in db.MovimientosPolizas
                    where data.Id == n.IdCuenta
                    group n by new { n.Importe} into g
                    let sumaTotal = (g.Sum(n => n.Importe))
                    select sumaTotal)).Sum();

Upvotes: 1

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