How to break the "circular reference" in NHibernate

Question

I meet the same issue just like the following:

NHibernate - not-null property reference a null or transient value

And the root reason is just like what Alun Harford said: "you're saving an entire object graph, and that graph is circular". see the following code

public class ApplyAuthorization : Activity
{
    public virtual ApplyStatus Status { get; set; }
    public virtual void Apply(Launch launch)
    {
        Status = Status ?? new ApplyStatus
        {
            For = this
        };
        Status.Update(launch);
    }
}

So the relationship is bidirectional: ApplyAuthorization -(Status)-> ApplyStatus and at the same time ApplyStatus -(For)-> ApplyAuthorization.

Now I know the reason but how to handle it?

Are your entities ids database generated ? – jbl Dec 17 '13 at 09:58 — jbl, Dec 17 '13 at 09:58
HasOne doesn't work, too. – freeflying Dec 17 '13 at 12:47 — freeflying, Dec 17 '13 at 12:47
Strange!!! Can't reproduce the issue. It works??? – freeflying Dec 17 '13 at 15:12 — freeflying, Dec 17 '13 at 15:12

score 0 · Accepted Answer · answered Dec 17 '13 at 15:19

0

I find the root cause but don't know deeply.

References(m => m.For).Not.Nullable();

The issue resolved if I remove the setting Not.Nullable().

But I don't know how to handle if the DBA require the Not Null constraint.

answered Dec 17 '13 at 15:19

freeflying

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How to break the "circular reference" in NHibernate

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