ASP.NET MVC Array of Children Foreign key Non-Nullable - asp.net-mvc-3

Question

So I have 2 Models setup like this:
class Job { ... List<Restriction> userRestrictions {set; get; ... }
2nd Model:
Restriction { public int Id { get; set; } ... public int JobID { get; set; } }
Now, when I edit a job, I fetch the Restrictions via:
job = db.Jobs.Where(i => i.Id == id).Include(r => r.UserRestrictions).First();
So I iterate through UserRestrictions and manually make them:
#for (ind = 0; ind < Model.UserRestrictions.Count; ind++)
{
JaASv1.Models.Restriction p = Model.UserRestrictions[ind];
<tr>
<td>
<input type="hidden" name="UserRestrictions[#(Counter + ind)].Id" value="#p.Id" />
<input type="hidden" name="UserRestrictions[#(Counter + ind)].JobId" value="#Model.Id" />
</td>
My Post Method:
public ActionResult Edit(Job job, string ProjTypeOther, string VenderOther, string FoldingOther, string BindingOther)
...
db.Entry(job).State = EntityState.Modified;
...
for (int iter = iterStart; iter >= 0; iter--)
{
Restriction r = job.UserRestrictions[iter];
db.Entry(r).State = EntityState.Modified;
if (r.Permissions == 0)
{
DelPermission(sPath, r.AdName); // Folder Permission things
job.UserRestrictions.Remove(r);
continue;
}
else if (r.Permissions == 1 )
{
AddPermission(sPath, r.AdName, readRights); // Folder Permission things
}
else if (r.Permissions == 2)
{
AddPermission(sPath, r.AdName, writeRights); // Folder Permission things
}
}
db.SaveChanges();
I get the following error on db.SaveChanges():
The relationship could not be changed because one or more of the
foreign-key properties is non-nullable.
I look through all the job.UserRestrictions and see they all have their JobID posted, I even looked in the database context and saw that there aren't any Foreign Keys with NULLs in them, so I don't know what this error is talking about.
Am I perhaps doing something wrong?
I've tried setting each Restriction state to Modified. That didn't seem to work.
I'm open to any suggestions.
Thanks!

Answer 1

So, what I ended up doing is the following:
Pulling all the UserRestrictions currently in the database.
Upon iterating through the post data, I check for the corresponding item in the database. I also set the UserRestrictions from the Post object to null so ASP doesn't try to re-insert into the table.
If the item doesn't exist, I add the item into the database.
I modify the item from the database instead of the post data one.
I had hoped ASP.NET would handle everything for me, but I guess I can't expect it to do it all.
List<Restriction> fromDB = db.Restrictions.Where(r => r.JobId == job.Id).ToList();
List<Restriction> newPost = job.UserRestrictions;
job.UserRestrictions = null;
for (int iter = iterStart; iter >= 0; iter--) {
... // Logic to handle post item
Restriction b;
try
{
b = fromDB.Where(f => f.Id == r.Id).First();
}
catch (Exception er)
{
// No record exists yet
b = r;
db.Restrictions.Add(b);
}
// Modify values of b to the values from post data
}
db.SaveChanges();
Sorry for strange indentation, StackOverflow should use bbcode instead of whitespace :x