CODEWITHSUNDEEP
ioscore-datarelationship
Nike Kov
Nike Kov

Reputation: 13698

Core Data How to set a value for relationship?

Assume, i have One-to-Many relationship between parent and childs.

How can i set child's parent by code? Something like: 

[child setValue: ParentManagedObject forKey: ParentRelationship];

Where child - in child managedObject which has relationship to parent.
ParentManagedObject - is object of parent, which is fetched to singletone, when app starts
ParentRelationship - is a key in .xcdatamodeld

I know that i can create NSManagedObjectSubclass for parent and child and do it like 

child.ParentRelationship = ParentManagedObject;

but i want to know how to do i without creating subclasses.

Upvotes: 1

Views: 1264

Answers (1)

bteapot
bteapot

Reputation: 2027

Of course you can use KVC to get or set NSManagedObject's properties.

For one-to-one or one-to-many relationship you can use:

[child setValue:parent forKey:parentKey];

For many-to-one or many-to-many use:

NSMutableSet *relationshipSet = [parent mutableSetValueForKey:childrenKey];
[relationshipSet addObject:child];

Where parent and child is NSManagedObject instances.

Upvotes: 2

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