Question

I’ve inherited a database and I’m trying to map it to Fluent NHibernate.
I have the following schema:

CREATE TABLE [Signatures](
    [Id] [int] IDENTITY(1,1) PRIMARY KEY CLUSTERED NOT NULL,
    -- Other Fields....
)

CREATE TABLE [SignoffSteps](
    [Id] [int] IDENTITY(1,1) PRIMARY KEY CLUSTERED NOT NULL,
    [SignatureId] [int] NULL REFERENCES [Signatures]([Id]),
    -- Other Fields....
)

And I’m attempting to map it to the following
(Extra properties and mappings omitted):

public class SignoffStep
{
    public virtual int Id { get; set; }
    public virtual Signature Signature { get; set;}

    public class Map : ClassMap<SignoffStep>
    {
        public Map()
        {
            Table("SignoffSteps");
            Id(x => x.Id);

            References(x => x.Signature, "SignatureId")
                .Nullable()
                .ForeignKey("FK_SingoffSteps_Signatures")
                .Cascade.All()
                .Not.LazyLoad();
        }
    }
}

public class Signature
{
    public virtual int Id { get; set; }

    public class Map : ClassMap<Signature>
    {
        public Map()
        {
            Table("Signatures");
            Id(x => x.Id);
        }
    }
}

This works great, except for one annoyance: deleting Signatures. I can make it work if I manually delete the signature:

session.Delete(signoffStep.Signature);
signoffStep.Signature = null;

But what I’d like to do is just set the Signature property on the signoff step to null, and have NHibernate automatically delete the child. Is there a way to setup my mapping to do this?

EDIT: Setting Cascade to “all-delete-orphan” not doable:

Answer 1

I ended up having a “ToDelete” property on the Signature, and manually deleting them while I’m saving. I don’t like this b/c it break the abstraction but it works for now.

I think to really fix it I wanted to, I would have had to redo the tables and associations a bit. Unfortunately this was out of the question in this case.