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Fluent NHibernate Mapping is installed on AllDeleteOrphan, but still trying to reset the foreign key in the database

I get an error with NHibernate when I try to execute ISession.Delete on any table with a one-to-many relationship.

NHibernate is trying to set the foreign key of the parent table in the child table to null, rather than just deleting the child table.

Here is my domain:

public class Parent
{

    public Parent()
    {
        _children = new List<Child>();
    }

    public int Id { get; set; }
    public string SimpleString { get; set; }
    public DateTime? SimpleDateTime { get; set; }

    private IList<Child> _children;
    public IEnumerable<Child> Children
    {
        get { return _children; }
    }
    public void AddChild(Child child)
    {
        child.Parent = this;
        _children.Add(child);
    }
}


public class Child
{
    public int Id { get; set; }
    public string SimpleString { get; set; }
    public DateTime? SimpleDateTime { get; set; }
    [JsonIgnore]
    public Parent Parent { get; set; }
}

I installed the Fluent NHibernate mappings as follows:

public class ParentMap : ClassMap<Parent>
{
    public ParentMap()
    {
        Not.LazyLoad();
        Id(x => x.Id);
        Map(x => x.SimpleString);
        Map(x => x.SimpleDateTime);

        HasMany(x => x.Children)
            .Not.LazyLoad()
            .KeyColumn("ParentId").Cascade.AllDeleteOrphan()
            .Access.ReadOnlyPropertyThroughCamelCaseField(Prefix.Underscore);

    }
}

public class ChildMap : ClassMap<Child>
{
    public ChildMap()
    {
        Not.LazyLoad();
        Id(x => x.Id);
        Map(x => x.SimpleString);
        Map(x => x.SimpleDateTime);
        References(x => x.Parent).Not.Nullable().Column("ParentId").Cascade.All().Fetch.Join();
    }
}

I told NHibernate Cascade.AllDeleteOrphan(), but it is still trying to set the ParentId foriegn key to null here - this is the test I set:

public void Delete_GivenTableWithChildren_WillBeDeletedFromDB()
{
    int id;
    using (var createSession = MsSqlSessionProvider.SessionFactory.OpenSession())
    {
        var parent = new Parent();
        parent.AddChild(new Child { SimpleString = "new child from UI" });

        using (var trx = createSession.BeginTransaction())
        {
            createSession.Save(parent);
            trx.Commit();
            id = parent.Id;
        }
    }

    using (var firstGetSession = MsSqlSessionProvider.SessionFactory.OpenSession())
    {
        var result = firstGetSession.Get<Parent>(id);
        Assert.IsNotNull(result);
    }

    using (var deleteSession = MsSqlSessionProvider.SessionFactory.OpenSession())
    {
        using (var trx = deleteSession.BeginTransaction())
        {
            deleteSession.Delete("from " + typeof(Parent).Name + " o where o.Id = :Id", id, NHibernateUtil.Int32);
            trx.Commit();
        }
    }

    using (var session = MsSqlSessionProvider.SessionFactory.OpenSession())
    {
        var result = session.Get<Parent>(id);
        Assert.IsNull(result);
    }
}

What happens after the line deleteSession.Deleteafter trying the following SQL:

exec sp_executesql N'UPDATE [Child] SET ParentId = null WHERE ParentId = @p0',N'@p0 int',@p0=5

with:

NHibernate.Exceptions.GenericADOException : could not delete collection: [SaveUpdateOrCopyTesting.Parent.Children#5][SQL: UPDATE [Child] SET ParentId = null WHERE ParentId = @p0]
  ----> System.Data.SqlClient.SqlException : Cannot insert the value NULL into column 'ParentId', table 'SaveUpdateCopyTestingDB.dbo.Child'; column does not allow nulls. UPDATE fails.
The statement has been terminated.

- , , , NHibernate ?

Dave

+5
2

.Inverse() ParentMap HasMany, :

HasMany(x => x.Children)
        .Not.LazyLoad()
        .KeyColumn("ParentId").Cascade.AllDeleteOrphan().Inverse()
        .Access.ReadOnlyPropertyThroughCamelCaseField(Prefix.Underscore);
+19

, , HQL.

:

var parent = deleteSession.Load<Parent>(id)
deleteSession.Delete(parent);

, . Load , , .

0

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