我没有从 ASP.NET MVC 中的控制器获取值

Question

I am writing an application in ASP.NET MVC 5, with Entity Framework 6.0, that based on a selected date, I send this date to a controller that passes it to a stored procedure, this procedure based on that date, counts the number of people and returns the value to the controller and "supposedly" should pass it back to ajax, so that using JavaScript can process it and show the result in the view; the code is the following:

$("#FechConsult").change('click', function () {
        $.ajax({
            type: 'POST',
            dataType: 'Json',
            url: "/Home/CuentaUser",
            data: { FechaInsc: $("#FechConsult").val() },
            success: function (data) {
                var CantidadUsr = result[0];
                $("#TotCupos").val(CantidadUsr.CantiPer);
                cupos = ParseInt(CantidadUsr.CantiPer - TotalUsr);
                if ((cupos >= 15) || (cupos <= 20)) {
                    $("#TotCupos").css({ "background": "#b5ff33" });
                }
                else {
                    if ((cupos >= 10) || (cupos <= 14)) {
                        $("#TotCupos").css({ "background": "#e9f00e" });
                    }
                    else {
                        if ((cupos >= 1) || (cupos <= 9)) {
                            $("#TotCupos").css({ "background": "#e85e0a" });
                            $("#mensaje").show();
                            $("#mensaje").val("Ha Llegado Casi Al Limite de Cupos Diarios");
                        }
                        else {
                            if ((cupos = TotalUsr)) {
                                $("#mensaje").show();
                                $("#mensaje").val("Ha Llegado A Límite Máximo de Personas, Seleccione Otro Dia");
                                $("#PassWord").focus();
                            }
                        }
                    }
                }
            }
        })
    });

then this happens to the controller:

[HttpPost]
    public ActionResult CuentaUser(Inscripcion inscripcion)
        {
            using (CtaUsr = new Drillco_InscripcionEntities())
            {
                var CantiPer =  CtaUsr.SP_Sel_Cta_PersXFecha(Convert.ToString(inscripcion.FechaInsc));
                return Json(CantiPer, JsonRequestBehavior.AllowGet);
            }
        }

The stored procedure is as follows:

ALTER procedure [dbo].[SP_Sel_Cta_PersXFecha]
    @FechInsc varchar(10)
AS
BEGIN
    SELECT COUNT(idOper) AS CantP
    FROM Inscripcion
    WHERE FechaInsc = CONVERT(datetime, @FechInsc, 103)
END

The problem: is that after calling the stored procedure, the ajax does not receive the value returned by the controller, when I do F12 in the browser, it tells me that there is a 500 error and it does not recognize the name of the controller, I have given a thousand turns and I have not reached any solution, could someone tell me that I am doing wrong?

Answer 1

One thing, your ajax call is passing FechaInsc: $("#FechConsult").val() but your stored procedure is expecting a parameter called 'inscripcion`. These names & types should match. From what it looks like your Ajax call is sending a string for the updated "inscription" for an object, but the server-side code is expecting an entity back.

It should probably be something more like:

public ActionResult CuentaUser(string fechaInsc)
{
    using (CtaUsr = new Drillco_InscripcionEntities())
    {
        var CantiPer =  CtaUsr.SP_Sel_Cta_PersXFecha(fechaInsc);
        return Json(CantiPer, JsonRequestBehavior.AllowGet);
    }
}

However, from this if that stored procedure is updating a value on a specific record, I don't see how it will know which row to update. Normally for an Update method you'd pass enough data to identify the row to update, and the values:

public ActionResult CuentaUser(int inscriptionId, string fechaInsc)

Or a data container (a POCO ViewModel or DTO, Not an entity) that contains the ID(s) and data to be updated.

It is worth noting that the whole point of using Entity Framework is to replace concerns about talking to a data layer. Define the entities, configure EF to map those relationships to the respective tables, and let EF manage the generation and execution of the SQL statements. If the intention is to write stored procedures to handle updates and selects, then you're better off just using ADO.Net.

With EF, an update method would look more like:

public ActionResult CuentaUser(int inscripcionId, string fechaInsc)
{
    using (context = new DrillcoDbContext())
    {
        var inscripcion = context.Inscripcions.Single(x => x.InscripcionId == inscripcionId);
        inscripcion.FechaInsc = fechaInsc;
        context.SaveChanges();
        return Json(inscripcion, JsonRequestBehavior.AllowGet);
    }
}

This is making a lot of guesses about the objects your application would be working with. However the fundamental difference would be to pass the ID of the entity to update along with the updated value(s), use the DbContext to fetch that entity by ID, update the value, and call SaveChanges on the DbContext . EF builds the SQL needed for the values that have changed if and only if those values actually change. No writing/calling stored procedures required.