没有与查询匹配的结果

Question

I'm not sure if this is a matter of the IBAction below the didReceiveMemoryWarning not calling the same variables as the query below viewDidLoad method, or some other issue. But when I run this code, I get an error that says "no results matched the query" and "the operation couldn't be completed. Parse error 101." Could anyone tell me why that is?

    override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    var voteCount1 = PFObject(className: "VoteCount")
    voteCount1["choices"] = 2
    voteCount1["votes"] = Int()
    voteCount1["votes2"] = Int()
    voteCount1["optionName"] = String()
    voteCount1["optionName2"] = String()
    voteCount1["objectId"] = String()

    var voteCount2 = PFObject(className: "VoteCount2")
    voteCount2["choices"] = 3
    voteCount2["votes"] = Int()
    voteCount2["votes2"] = Int()
    voteCount2["votes3"] = Int()
    voteCount2["optionName"] = String()
    voteCount2["optionName2"] = String()
    voteCount2["optionName3"] = String()

    var voteCount3 = PFObject(className: "VoteCount3")
    voteCount3["choices"] = 4
    voteCount3["votes"] = Int()
    voteCount3["votes2"] = Int()
    voteCount3["votes3"] = Int()
    voteCount3["votes4"] = Int()
    voteCount3["optionName"] = String()
    voteCount3["optionName2"] = String()
    voteCount3["optionName3"] = String()
    voteCount3["optionName4"] = String()

    var query = PFQuery(className: "VoteCount")
    query.countObjectsInBackgroundWithBlock {
        (count: Int32, error: NSError!) -> Void in
        if error == nil {
            let randNumber = arc4random_uniform(UInt32(count))
            query.whereKey("voteNumber", equalTo: NSNumber(unsignedInt:randNumber))
            query.getFirstObjectInBackgroundWithBlock {
                (voteCount1: PFObject!, error: NSError!) -> Void in
                if error != nil {
                    NSLog("%@", error)
                } else {
                    let votes = voteCount1["votes"] as Int
                    let votes2 = voteCount1["votes2"] as Int
                    let option1 = voteCount1["optionName"] as String
                    let option2 = voteCount1["optionName2"] as String
                    self.showOption1.text = "\(option1)"
                    self.showOption2.text = "\(option2)"
                }

            }
        } else {
            println("error \(error)")
        }
        }


}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}




@IBOutlet weak var pollResults: UILabel!

@IBAction func addVote1(sender: AnyObject) {
    var query = PFQuery(className: "VoteCount")
    query.getObjectInBackgroundWithId("objectId") {
        (voteCount1: PFObject!, error: NSError!) -> Void in
        if error != nil {
            NSLog("%@", error)
        } else {
            voteCount1.incrementKey("votes")
            voteCount1.saveInBackgroundWithTarget(nil, selector: nil)
            let votes = voteCount1["votes"] as Int
            let votes2 = voteCount1["votes2"] as Int
            self.pollResults.text = "\(votes)   \(votes2)"
        }
        }
}

@IBOutlet weak var pollResults2: UILabel!

@IBAction func addVote2(sender: AnyObject) {
    var query = PFQuery(className: "VoteCount")
    query.getObjectInBackgroundWithId("objectId") {
        (voteCount1: PFObject!, error: NSError!) -> Void in
        if error != nil {
            NSLog("%@", error)
        } else {
            voteCount1.incrementKey("votes2")
            voteCount1.saveInBackgroundWithTarget(nil, selector: nil)
            let votes = voteCount1["votes"] as Int
            let votes2 = voteCount1["votes2"] as Int
            self.pollResults2.text = "\(votes)   \(votes2)"
        }
        }
    }
}

What I'm trying to do is call the values for the variables "votes" "votes2" "option1" and "option2" from a random row on my Parse database. I've created a column of Int data called "voteNumber" that each contains a number 1 to 1000 and I believe by calling a row with a random number I should be able to call all the appropriate data from a random row. I'm just not sure if I'm bridging the query within the viewDidLoad method with the IBActions underneath the closing of the didReceiveMemoryWarning method.

Answer 1

Looking at the definition, equalTo: expects an id which translates to AnyObject in Swift. In both Swift and Objective-C you would need to convert the number to a NSNumber object to get the code to work.

Approach 1: Manual conversion

The first approach is to simply create a new NSNumber wrapping the value:

Objective-C:

// Option 1:
[query whereKey:@"voteNumber" equalTo: @(randNumber)];

// Option 2:
[query whereKey:@"voteNumber" equalTo: [NSNumber numberWithUnsignedInt:randNumber]];

Swift:

query.whereKey("voteNumber", equalTo: NSNumber(unsignedInt:randNumber))

Approach 2: Objective-C bridging

Certain types in Swift qualify for automatic bridging to Objective-C types. While UInt32 doesn't qualify, it can safely upcast to UInt which does:

let randNumber = UInt(arc4random_uniform(UInt32(count)))
query.whereKey("voteNumber", equalTo: randNumber)