聚合根的流畅NHibernate级联删除约定

Question

Question is: how to write convention that prevents deleting entity reference if it inherits from type Root ?

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I'm using fluent nhibernate and it's auto mapping feature. Turned on cascading delete by default.

Everything was really cool until I finally hit case when I need to actually delete aggregate root that references another one.

I got roots User and Application . User registers Applications . If it's registered by mistake, there is small time gap in which User with role Admin can remove it (I'm kind a sure I won't ever need that data).

When User removes Application , because of cascading delete, nhibernate removes User itself (what an irony...).

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I'm unsure how to specify SaveUpdate cascading for Application->User association only:

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Does the trick:

m.References(x=>x.RegisteredBy).Cascade.SaveUpdate(); //RegisteredBy.Type==User

Additionally, told fnh where to look for overrides:

var m=new AutoPersistenceModel(storeCfg);
m.UseOverridesFromAssembly(assembly);

Answer 1

You can override behaviour of cascading for Application->User association. You need to set SaveUpdate() instead of all-delete-orphan. To do this you will need to implement IAutomappingOverride<Application>