@objc(User)
class User: NSManagedObject {
    @NSManaged var id: Int64
    @NSManaged var firstName: String?
    @NSManaged var lastName: String?
    @NSManaged var salary: Int64
}

extension User: QueryProtocol { }

let user = try? User.findFirst()
    .sorted(by: \User.firstName)
    .execute(in: context)

let allJohns = try? User.findAll()
    .where(\User.firstName, equals: "John")
    .execute(in: context)

let ranged = try? User.findRange(2..<5)
    .sorted(by: \User.id)
    .execute(in: context)

let usersCount = try? User.getCount()
    .execute(in: context)

let minId = try? User.getMin(keyPath: \User.id)
    .execute(in: context)

let maxId = try? User.getMax(keyPath: \User.id)
    .execute(in: context)

let deleteCount = try? User.deleteAll()
    .where(\User.firstName, equals: "John")
    .execute(in: context)

let result = try User.getDistinct()
    .propertiesToFetch([\User.firstName])
    .aggregate(keyPath: \User.salary, function: "sum:", saveAs: "totalSalary")
    .group(by: \User.firstName)
    .execute(in: context)

let userFetchedResults = try? User.fetchResults()
    .group(by: \User.firstName)
    .sorted(by: \User.firstName)
    .sorted(by: \User.lastName)
    .execute(in: context)

pod 'FetchKit'