Objective-C : Relationship to own class (CoreData)
In my project there is a managed object called "Group".
This object itself can contain child group objects.
How do I solve this situation in CoreData and in the FetchedResultsController?
My first shot:
http://i46.tinypic.com/zvonp开发者_高级运维d.png
Thanks, Dan
I would make two separate relationships that are inverses of each other.
Group has a to-many relationship with Group named "children", Group also has a to-many relationship with Group named "parents" and they are inverses of each other.
Or, if your data model only calls for one parent: Group has a to-many relationship with Group named "children", Group also has a to-one relationship with Group named "parent" and they are inverses of each other.
It looks correct. Usually you term the other entities children instead of parents but that is just a matter of style and convention.
You would fetch the child/parent relationship just as you would any other attribute. The only gotcha is that each relationship attribute is returned as a NSSet so you have to find the child you want inside of the set.
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