NHibernate and HasMany mapping - asp.net-mvc

Question

i have trivial mapping for two entities: poll and polloption
Poll:
public class PollMap : ClassMap<Poll>
{
public PollMap() {
Id(x => x.Id);
Map(x => x.Content);
HasMany(x => x.PollOptions).Cascade.All();
}
}
PollOption:
public class PollOptionMap : ClassMap<PollOption>
{
public PollOptionMap() {
Id(x => x.Id);
Map(x => x.Content);
References(x => x.Poll);
}
}
in test code im trying to remove the first polloption of poll entity
Test code:
[Transaction]
public ActionResult Add() {
var poll = new Poll() {
Content = "poll",
PollOptions = new List<PollOption>() {
new PollOption(){
Content="PollOption#1"
},
new PollOption(){
Content="PollOption#2"
}
}
};
GetSession.Save(poll);
return Content("Added");
}
[Transaction]
public ActionResult Removed() {
var poll = GetSession.Query<Poll>().FirstOrDefault();
poll.PollOptions.RemoveAt(0);
GetSession.Update(poll);
return Content("Updated");
}
when the remove action fired it not deleting polloption from db instead it set null in my foreign key :(
ps. google not helped

Answer 1

Cascade.All() only deletes the child object if the parent is deleted. If you want the childs to get deleted when they are removed from the collection, you need Cascade.AllDeleteOrphan().
Additional note: You also have to mark one side of your bidirectional association as Inverse(). More info about that here: http://nhibernate.info/doc/nh/en/index.html#collections-bidirectional