ios - 来自私有(private)区域的 CKQuery 仅返回 CloudKit 中的前 100 个 CKRecords

Question

Cloudkit private default zone 的查询结果是否有限制？我不知道为什么我只收到带有以下查询的前 100 条记录:

let p = NSPredicate(format: "(type == 'entered') AND (timestamp >= %@) AND (timestamp <= %@)", from, to)
let q = CKQuery(recordType: self.beaconRecordType, predicate: p)
q.sortDescriptors = [NSSortDescriptor(key: "timestamp", ascending: true)]
self.privateDatabase?.performQuery(q, inZoneWithID: nil, completionHandler: { results, error in

    //count = 100
    println(results.count)

}

---

好的。正如埃德温在回答中提到的那样，解决方案是使用 CKQueryOperation 来获取初始数据 block ，然后使用 completionBlock 中的“游标”来触发另一个操作。这是一个例子:

更新

func fetchBeacons(from:NSDate, to:NSDate) {

    let p = NSPredicate(value: true)
    let q = CKQuery(recordType: self.beaconRecordType, predicate: p)

    let queryOperation = CKQueryOperation(query: q)

    queryOperation.recordFetchedBlock = fetchedARecord

    queryOperation.queryCompletionBlock = { [weak self] (cursor : CKQueryCursor!, error : NSError!) in

        if cursor != nil {
            println("there is more data to fetch")
            let newOperation = CKQueryOperation(cursor: cursor)
            newOperation.recordFetchedBlock = self!.fetchedARecord
            newOperation.queryCompletionBlock = queryOperation.queryCompletionBlock
            self!.privateDatabase?.addOperation(newOperation)
        }

    }

    privateDatabase?.addOperation(queryOperation)
}

var i = 0
func fetchedARecord (record: CKRecord!) {
    println("\(NSDate().timeIntervalSinceReferenceDate*1000) \(++i)")
}

Answer 1

100 是标准查询的默认限制。这个数额不是固定的。它可能因 iCloud 总负载而异。如果你想影响那个数量，那么你需要使用 CKQueryOperation 并像这样设置 resultsLimit: operation.resultsLimit = CKQueryOperationMaximumResults;CKQueryOperationMaximumResults 是默认值，并将其限制为 100(大部分时间)。不要将该值设置得太高。如果你想要更多的记录，那么使用queryCompletionBlock的游标继续读取更多的记录。