Core Data - How to fetch an entity with max value property

Question

I have a entity Person with a property personId (personId is unique)

How can I fetch the Person with the max personId?

(I want to f

Answer 1

In addition to Ryan's answer, in Swift today, NSManagedObject's execute(_:) returns a NSPersistentStoreResult object, which need some extra code to retrieve the value:

// Cast `NSPersistentStoreResult` to `NSAsynchronousFetchResult<NSDictionary>`
let fetchResult = moc.execute(request) as! NSAsynchronousFetchResult<NSDictionary>

// Retrieve array of dictionary result
let dictsResult = fetchResult.finalResult

// Retrieve and cast the real result
let key = /* `expressionDescription.name` */
let result = dictsResult.first!.object(forKey: key) as! /* Your type, depending on `expressionDescription.expressionResultType` */

Note: Force unsafe type cast are used above to simplify code, in real case scenario, you should always avoid this.