Fetch a random row from a CoreData entity

RandomFetch.swift

func RandomFetch() -> Item? {
    let req = NSFetchRequest<NSFetchRequestResult>(entityName: "MyEntity")
    req.predicate = NSPredicate(format: "duedate > %@", due as NSDate)

    // find out how many items are there
    let totalresults = try! mContext.count(for: req)
    if totalresults > 0 {
        // randomlize offset
        req.fetchOffset = Int.random(in: 0..<totalresults)
        req.fetchLimit = 1

        let res = try! mContext.fetch(req) as! [Item]
        return res.first
    }
    
    return nil
}