NSFetchRequest how to fetch different objects?

Question

I want to fetch a result that doesn't have some same parameter.

like this.

Sample:

Obj1.title= @"1"
Obj2.title= @"3"
Obj3.title= @"3"
Obj4.title= @"3"
Obj5.title= @"4"

Result:

Obj1, Obj2, Obj5

Is it possible in NSFetchRequest?

Answer 1

Yes this can be done by setting the returnDitinctProperties on the fetchRequest:

request.returnsDistinctResults = YES;

For this to work, you also need to set which properties need to be fetched:

request.propertiesToFetch = @[@"title"];

Fore more details, see Apple's documentation: https://developer.apple.com/library/ios/documentation/DataManagement/Conceptual/CoreDataSnippets/Articles/fetchExpressions.html

Answer 2

You can add all your Objects.title to an NSArray myArray, an then you can add the myArray to an NSSet to have an NSSet with unique titles.

NSSet *uniqueTitles = [NSSet setWithArray:myArray];