Error updating an entity: Conflict with Foreign Key

Question

Hello!

On this action:

[HttpPost, ActionName("Test")]
    [ValidateAntiForgeryToken]
    public async Task TestPost(Machine machinetoUpdate)
    {
        var machine = _context.Machines.Where(m => m.Id == machinetoUpdate.Id).FirstOrDefault();

        machine.PUnit = machinetoUpdate.PUnit;
        machine.StoreID = machinetoUpdate.StoreID;
        machine.Status = machinetoUpdate.Status;
        _context.SaveChanges();
        PopulateMachineTypeDropDownListStore();

        return View(await _context.Machines.AsNoTracking().ToListAsync());
    }

I'm getting an error while trying to update StoreID.

SqlException: The UPDATE statement conflicted with the FOREIGN KEY constraint "FK_Machine_Store_StoreID". The conflict occurred in database "Application4", table "dbo.Store", column 'StoreID'. The statement has been terminated.

StoreID is a foreign key for the Machine class:

public class Machine
{
    public int Id { get; set; }
    public int TypeID { get; set; }
    public int SupplierID { get; set; }
    public int StoreID { get; set; }
    [StringLength(60)]
    [Display(Name = "Serial")]
    public string MchName { get; set; }
    [DataType(DataType.Date)]
    [DisplayFormat(DataFormatString ="{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
    [Display(Name = "Fecha de Compra")]
    }

This is the Store class:

public class Store
{
    [Key]
    public int StoreID { get; set; }
    public int DistrictID { get; set; }
    [Required]
    [StringLength(60)]
    public string StoreName { get; set; }
    [StringLength(60)]
    public string StoreAddress { get; set; }

    public virtual ICollection Machines { get; set; }
    public virtual District Districts { get; set; }
}

I don't know why StoreID won't update. I'm not inserting a StoreID that does not exist in the Store model, since I choose it from a dropdownlist.

 

This is  the view:

 

@foreach (var item in Model)
{
    <form asp-action="Test" asp-route-id="@item.Id">
        <table class="table">
            <tbody>
                <tr>
                    <td>
                        <input type="hidden" asp-for="@item.Id" />
                        <div class="form-group">
                            <div class="col-md-10">
                                <input asp-for="@item.MchName" readonly class="form-control" />
                                <span asp-validation-for="@item.MchName" class="text-danger"></span>
                            </div>
                        </div>
                    </td>
                    <td>
                        <div class="form-group">
                            <div class="col-md-10">
                                <select asp-for="@item.StoreID" class="form-control" asp-items="ViewBag.StoreID">
                                </select>
                                <span asp-validation-for="@item.StoreID" class="text-danger"></span>
                            </div>
                        </div>
                    </td>
                    <td>
                        <div class="form-group">
                            <div class="col-md-10">
                                <input type="number" max="10" step=".1" asp-for="@item.PUnit" class="form-control" />
                                <span asp-validation-for="@item.PUnit" class="text-danger"></span>
                            </div>
                        </div>
                    </td>
                    <td>
                        <div class="form-group">
                            <div class="col-md-10">
                                <select name="Status" asp-for="@item.Status" class="form-control">
                                    <option value="0">Operativo</option>
                                    <option value="1">Nuevo Item</option>
                                    <option value="2">Reparación</option>
                                </select>
                                <span asp-validation-for="@item.Status" class="text-danger"></span>
                            </div>
                        </div>
                    </td>
                    <td>
                        <input type="submit" value="Update" class="btn btn-default" />
                    </td>
                </tr>
            </tbody>
        </table>

    </form>}

 

 

I don't know if the dropdownlist for the Store might be sending a StoreID value wrong. It seems it's ok, so I don't know.

 

Thanks in advance for any help.

 

Update: More Info 

 

I believe my problem could be on my Get Method.

 

My view (Test.cshtml) is correctly loading and showing the info of all the items in the Machine class in the table, including the StoreID, however, my Get Method is this:

 

public async Task Test()
        {
            PopulateMachineTypeDropDownListStore();
            return View(await _context.Machines.AsNoTracking().ToListAsync());

        }

Is it possible that it does not matter if my View is showing what I want because my Get Method is not capturing any info on the StoreID? And thus, when I hit the 'Update' button it might be trying to duplicate the StoreID and for that I get the error?

Answer 1

If you want to display email notification in user system, then I am not sure you can achieve that. Because it is user system and you can't do any change through WebApp. 

 

If you want to display notification in web application to user then you can achieve it.

 

Answer 2

 Thanks guys

 

Regards

Sameer shaikh 

Answer 3

As Ramesh said, its not in your hand. its not logical.  

Answer 4

Hi Sameer,

 

Thats what I am saying, You cannot do it in your coding.. It have to be configured in their mail settings.

 

 

Answer 5

@Rakesh

 

sorry, Actually i didn't mention one thing i have User table that contain list of users and am going to send email to all.

 

if end users gmail/hotmail account is open,show him notification,

 

can i achive this kind of logic at my side i.e using coding.

 

Regards

Sameer Shaikh 

 

 

 

 

Answer 6

Hi Sameer,

 

 

I think you cannot achieve this in from your end. It has to be configured in receiver mail settings. 

 

You can send the mail to any mail services, which mean it may be an Yahoo,gmail or rediffmail whatever may be...

 

The mail receive notification wants to be configured in their mail settings.