I see following example of adding to-many relationship back to CoreData
where 'currentDog' have many 'walks'
walk.date = NSDate()
let walks = currentDog.walks!.mutableCopy() as! NSMutableOrderedSet
walks.addObject(walk)
currentDog.walks = walks.copy() as? NSOrderedSet
and this is the way they insert the new walk
I was wondering why is it done that way? when one can simply do
walk.date = NSData()
walk.dog = currentDog
A more general question. Why would there be a need to insert an object to a Set before saving? When you can simply set the relationship of an object to it's related object or parent.
If the relationship is ordered then you may want to insert into the set. If not, and assuming your relationship is bi-directional as all should be, then your second example of setting the to-one end of the relationship is preferred because it's less code and therefore easier to maintain and read.
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