I have a question regarding Realm on iOS.
I have an object in my Realm DB that looks like this:
class MyObject: Object {
dynamic var id: Int!
dynamic var val: String!
}
Let say I populate my table with those data:
| id | val |
|----|-----|
| 1 | A |
| 2 | B |
| 3 | A |
| 4 | B |
| 5 | A |
| 6 | A |
How can query my Realm DB to return the most represented value which is A?
Thanks
Realm doesn't have a native query that'll do exactly that, but you can combine Realm's KVC support with NSCountedSet to get this fairly easily:
import Foundation
import RealmSwift
class MyObject: Object {
dynamic var id: Int = 0
dynamic var val: String = ""
}
let realm = try! Realm()
try! realm.write {
for (index, value) in ["A", "B", "A", "B", "A", "A"].enumerate() {
realm.create(MyObject.self, value: [index, value])
}
}
let values = realm.objects(MyObject).valueForKey("val") as! [AnyObject]
let countedSetOfValues = NSCountedSet(array: values)
let maxElement = countedSetOfValues.allObjects.maxElement { first, second in
return countedSetOfValues.countForObject(first) < countedSetOfValues.countForObject(second)
}
maxElement // => "A"