CODEWITHSUNDEEP
objective-cioscore-data
Christian Loncle
Christian Loncle

Reputation: 1584

iOS: how to fetch all objects of nested relationship parent.child.theObjectsIWant

For one nested relationship I would do this:

NSMutableArray *allClusters = [NSMutableArray arrayWithArray:[form.clusters allObjects]];

But what should I do for? :

NSMutableArray *allQuestions = [NSMutableArray arrayWithArray:[form.clusters.questions allObjects]];

Both clusters and questions are one-to-many relationships.

Any help is welcome

Upvotes: 1

Views: 434

Answers (2)

bijan
bijan

Reputation: 1685

    NSSet *allQuestionsOfForm = [form valueForKeyPath:@"clusters.questions"];

EDIT:

The code above returns a nested set as glorifiedHacker said. To get a flattened set use:

    NSSet *allQuestionsOfForm = [form valueForKeyPath:@"[email protected]"];

Upvotes: 2

glorifiedHacker
glorifiedHacker

Reputation: 6420

It looks like you're dealing with nested sets, so you probably just need to iterate through the parent sets to collect the items in the child sets:

NSMutableArray *allQuestions = [NSMutableArray array];

for(Cluster *cluster in form.clusters) {
    [allQuestions addObjectsFromArray:[cluster.questions allObjects]];
}

If this isn't what you're after, then you'll need to add some more detail to your original question.

Upvotes: 1

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