Swift -从Cloudkit公共数据库获取所有记录

Question

您好，我正在尝试从cloudkit中的publicDB中获取所有记录，目前有2000多条记录。如何获取它们并将它们放入一个数组中？我已经尝试了这两种方法，但都没有成功。你能帮帮我吗？

1种方法

    let predicate = NSPredicate(value: true)
    let query = CKQuery(recordType: "Position", predicate: predicate)
    query.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]

publicDB.perform(query, inZoneWith: nil) { (results, error) -> Void in            

        if error != nil {

            DispatchQueue.main.async(execute: {  () -> Void in
                self.delegate?.errorUpdating(error: error! as NSError)
                return
            })
        } else {
            self.positionArray.removeAll(keepingCapacity: true)

            for record in results! {

                let position = Position(record: record as CKRecord, database: self.publicDB)
                self.positionArray.append(position)

            }
        }

            DispatchQueue.main.async(execute: {  () -> Void in
               /* my elaboration with the complete result */
            })



    }

2方法

    let predicate = NSPredicate(value: true)   
    let query = CKQuery(recordType: "Position", predicate: predicate)

    query.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]

    let qop  = CKQueryOperation(query: query)

    qop.resultsLimit = 3000        
    qop.recordFetchedBlock = { (record: CKRecord) in
        let position = Position(record: record, database: self.publicDB)
        self.positionArray.append(position)
        print(self.positionArray.count)
    }

    qop.queryCompletionBlock = { (cursor: CKQueryOperation.Cursor?, error: Error?) in
        DispatchQueue.main.async(execute: {  () -> Void in
        if let cursor = cursor {

            print("entro")
            let newOperation = CKQueryOperation(cursor: cursor)

            newOperation.recordFetchedBlock = qop.recordFetchedBlock
            newOperation.queryCompletionBlock = qop.queryCompletionBlock
            self.publicDB.add(newOperation)
        }

        else if let error = error {
            print("Error:", error)
        }
            // No error and no cursor means the operation was successful
        else {
            print("Finished with records:", self.positionArray)
            if(!all){
                // my elaboration
            }
            else{
                // my elaboration
            }
        }
        })
    }

    self.publicDB.add(qop)

使用第一种方法，我最多只能获取100条记录。使用第二种方法，我最多只能获取400条记录。但是我需要用2000多条记录填充我的数组，如何才能达到这个结果呢？

Answer 1

请你试试这个吧！

var口哨= CKRecord

func loadWhistles(completionHandler: (() -> Void)?) {
    let pred = NSPredicate(value: true)
    let sort = NSSortDescriptor(key: nomeDaTabela, ascending: ordemDaTabela)
    let query = CKQuery(recordType: "Cliente", predicate: pred)
    query.sortDescriptors = [sort]        

    let operation = CKQueryOperation(query: query)
    operation.desiredKeys = ["Name"]
    operation.resultsLimit = 2000

    var newWhistles = Whistle

    operation.recordFetchedBlock = { record in
        newWhistles.append(record)

    }


    operation.queryCompletionBlock = { [unowned self] (cursor, error) in
        DispatchQueue.main.async {
            if error == nil {
                //ViewController.isDirty = false
                self.clienteRecords = newWhistles
                self.clientesTableView.reloadData()
            } else {
                let ac = UIAlertController(title: "Fetch failed", message: "There was a problem fetching the list of whistles; please try again: \(error!.localizedDescription)", preferredStyle: .alert)
                ac.addAction(UIAlertAction(title: "OK", style: .default))
                self.present(ac, animated: true)
            }
        }
    }


    PublicDatabase.add(operation)
    completionHandler?()

}

Answer 2

每个fetch操作确实有400条记录的限制，因此您需要检查查询完成块返回的CKQueryCursor值，如果不是nil，则使用它CKQueryOperation(cursor: cursor)启动另一个操作。

所以原则上你的第二种方法是正确的。我猜你的问题是由线程问题引起的，尝试删除DispatchQueue.main.async(execute: { () -> Void in。

附注:看看它是如何在RxCloudKit中完成的(它会自动处理大的获取)，它绝对适用于获取1000+记录-- RecordFetcher.queryCompletionBlock(cursor: CKQueryCursor?, error: Error?)