Question

I have declared some Non-Content data in an Orchard CMS by defining the records and schema like this:

public class CountyRecord
{
    public virtual int Id { get; set; }
    public virtual string CountyName { get; set; }
    public virtual CountryRecord CountryRecord { get; set; }
}

public class CountryRecord
{
    public CountryRecord()
    {
        CountyRecords = new List<CountyRecord>();
    }
    public virtual int Id { get; set; }
    public virtual string CountryName { get; set; }
    public virtual IList<CountyRecord> CountyRecords { get; set; }
}

public class Migrations: DataMigrationImpl
{
    public int Create()
    {
        //COUNTIES
        SchemaBuilder.CreateTable(typeof(CountyRecord).Name, table => table
            .Column<int>("Id", col => col
                .PrimaryKey()
                .Identity())
            .Column<string>("CountyName")
            .Column<int>("CountryRecord_Id"));

        //COUNTRIES
        SchemaBuilder.CreateTable(typeof(CountryRecord).Name, table => table
            .Column<int>("Id", col => col
                .PrimaryKey()
                .Identity())
            .Column<string>("CountryName"));
    }
}

I then have two controllers handling the admin pages for these two entities. In the country controller I have the following actions:

    //DELETE
    [HttpGet, Admin]
    public ActionResult Delete(int countryId)
    {
        var country = CountryRepo.Get(countryId);
        if (country == null)
        {
            return new HttpNotFoundResult("Couldn't find the country with ID " + countryId.ToString());
        }
        return View(country);
    }

    [HttpPost, Admin, ActionName("Delete")]
    public ActionResult DeletePOST(CountryRecord country)
    {       
        foreach (CountyRecord county in CountyRepo.Fetch(c=>c.CountryRecord.Id==country.Id))
        {
            CountyRepo.Delete(county);
        }

        CountryRepo.Delete(country);
        OrchardServices.Notifier.Add(NotifyType.Information, T("Country '{0}' deleted successfully", country.CountryName));
        return RedirectToAction("Index");
    }

And this is the view that goes with that:

@model Addresses.Models.CountryRecord
<div class="manage">
@using (Html.BeginFormAntiForgeryPost("Delete"))
{
    <h2>Are you sure you want to delete this country and ALL its counties?</h2>
    @Html.HiddenFor(m => m.Id);
    @Html.HiddenFor(m => m.CountryName);
    @Html.ActionLink(T("Cancel").Text, "Index", "CountriesAdmin", new { AreaRegistration = "Addresses" }, new { style = "float:right; padding:4px 15px;" })
    <button class="button primaryAction" style="float:right;">@T("Confirm")</button>
}
</div>

However, here’s the issue, when I delete a country that still has counties assigned to it, it throws the following error:

a different object with the same identifier value was already associated with the session

Can anyone please help?

Thanks.

Answer 1

It’s because your DeletePOST() parameter is a CountryRecord. Orchard records are all proxied by the NHibernate framework and MVC’s ModelBinder can’t properly create them for you.

What you need to do instead is like what you do in the non-POST method: accept just the integer ID of the CountryRecord, fetch the record fresh from the repository, then delete it.