that's because you haven't made a link from the child to the parent.
when adding records to child lists in nhibernate it is common to add both
add/remove functions that manage the lists. Here's an example using a
child collection of ContactInformation.
public virtual void AddContactInformation(ContactInformation
contactInformation)
{
if (ContactInformation.Contains(contactInformation))
return;
contactInformation.Contact = this;
ContactInformation.Add(contactInformation);
}
public virtual void RemoveContactInformation(ContactInformation
contactInformation)
{
if (!ContactInformation.Contains(contactInformation))
return;
ContactInformation.Remove(contactInformation);
}
On Tue, Jan 21, 2014 at 2:38 PM, Mike Christensen <[email protected]>wrote:
> Looks like this almost works.. Setting the initial ID to Guid.Empty
> definitely makes the problem go away.. I also set the mapping as:
>
> HasMany(x => x.Items)
> .KeyColumn("ShoppingListId")
> .Inverse()
> .Cascade.All();
>
> Now I can add the item as such:
>
> dbList.Items.Add(new ShoppingListItems
> {
> Raw = source.Raw,
> UserId = identity.UserId
> });
>
> And it will create the new item. However, one small problem: The new item
> does NOT get linked to dbList. Its ShoppingListId property is left as null.
>
> Shouldn't adding a new item to dbList.Items make the ShoppingListId get
> set to the primary key of dbList? Or, do I have to manually specify this?
> Thanks!
>
> Mike
>
>
> On Tue, Jan 21, 2014 at 1:32 AM, Pete Appleton <[email protected]
> > wrote:
>
>> A few things that cross my mind:
>>
>>
>>
>> 1. You'll definitely need an appropriate Cascade style for the "HasMany"
>> mapping on ShoppingLists.Items, e.g. SaveUpdate - not sure which mapping
>> system you're using, so don't know the exact syntax
>>
>> 2. 99% of the time, this mapping should be 'Inverse'
>>
>> 3. It looks as you're manually assiging a new ID to the new
>> 'ShoppingListItems' object, which I suspect is causing NH to believe that
>> the new object is persistent.
>>
>>
>>
>> My general pattern for this sort of thing is as follows (pseudo-code for
>> interesting bits only):
>>
>>
>>
>> class ShoppingList {
>>
>> Guid Id { get; protected set; }
>>
>> ISet<ShoppingListItem> Items { get; protected set; }
>>
>>
>>
>> public ShoppingList() {
>>
>> this.Items = new …
>>
>> }
>>
>> }
>>
>>
>>
>> class ShoppingListLine {
>>
>> Guid Id { get; protected set; }
>>
>> public ShoppingList List { get; protected set; }
>>
>>
>>
>> ShoppingListLine(ShoppingList list) {
>>
>> this.List = list;
>>
>> this.List.Items.Add(this);
>>
>> }
>>
>>
>>
>> void Delete() {
>>
>> if(this.List != null) this.List.Items.Remove(this);
>>
>> this.List = null;
>>
>> }
>>
>> }
>>
>>
>>
>> var dbList = ….;
>>
>> var newItem = new
>> ShoppingListLine(dbList); // ctor
>> handles association maintenance
>>
>>
>>
>>
>>
>>
>>
>> /Pete
>>
>> *From:* [email protected] [mailto:[email protected]] *On
>> Behalf Of *Mike Christensen
>> *Sent:* 21 January 2014 00:47
>> *To:* nhusers
>> *Subject:* [nhusers] Adding a new item to a collection using Fluent
>> NHibernate doesn't INSERT the new row in the DB
>>
>>
>>
>> (StackOverflow question in case anyone wants
>> upvotes<http://stackoverflow.com/questions/21246584/adding-a-new-item-to-a-collection-using-fluent-nhibernate-doesnt-insert-the-new>
>> )
>>
>>
>>
>> I have a model called `ShoppingLists` and each `ShoppingLists` has a
>> collection of `ShoppingListItems` called `Items`. What I would *like* to
>> be able to do is add a new item to my list as such:
>>
>>
>>
>> dbList.Items.Add(new ShoppingListItems(Guid.NewGuid(),
>> identity.UserId, source.Raw));
>>
>>
>>
>> I would expect the `ShoppingListItems` to automatically be *linked* to
>> its parent `ShoppingLists` class, and for NHibernate to create the
>> appropriate SQL `INSERT` statement when the transaction is committed.
>> However, instead I get the exception:
>>
>>
>>
>> NHibernate.StaleStateException was unhandled
>>
>> HResult=-2146232832
>>
>> Message=Unexpected row count: 0; expected: 1
>>
>> Source=NHibernate
>>
>>
>>
>> What I have to do instead is create the object, save it, then add it to
>> the collection:
>>
>>
>>
>> var newItem = new ShoppingListItems(Guid.NewGuid(), identity.UserId,
>> source.Raw);
>>
>> newItem.ShoppingList = dbList;
>>
>> session.Save(newItem);
>>
>> dbList.Items.Add(newItem);
>>
>>
>>
>> I'd like to eliminate the need to do this. My mappings for
>> `ShoppingLists` is as such:
>>
>>
>>
>> Id(x => x.ShoppingListId);
>>
>>
>>
>> Map(x => x.UserId).Not.Nullable();
>>
>> Map(x => x.Title).Not.Nullable();
>>
>>
>>
>> HasMany(x => x.Items)
>>
>> .KeyColumn("ShoppingListId")
>>
>> .Cascade.Delete(); // If Shopping List is deleted, delete all the
>> Items that reference this list
>>
>>
>>
>> And my mappings for `ShoppingListItems` is:
>>
>>
>>
>> Id(x => x.ItemId);
>>
>>
>>
>> Map(x => x.Raw).Length(50);
>>
>> Map(x => x.Qty);
>>
>> Map(x => x.Unit);
>>
>> Map(x => x.UserId).Not.Nullable();
>>
>> Map(x => x.CrossedOut).Not.Nullable();
>>
>>
>>
>> References(x => x.Recipe).Column("RecipeId");
>>
>> References(x => x.Ingredient).Column("IngredientId");
>>
>> References(x => x.ShoppingList).Column("ShoppingListId");
>>
>>
>>
>> I've tried playing around with `Cascade.All()` on each, to no avoid. Any
>> ideas?
>>
>>
>>
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