用指针查询对象 - 解析，swift2
我有2个类，我有一个Activity类和JobPost类，在我的Activity类中有一个名为“postingJob”的对象，它是一个指针（JobPost），它存储每个发布作业的objectID。
我想要实现的是从活动中查询postingJob，但是我在下面的代码解析是一个错误。
let jobPostObject = PFObject(className: "JobPost")
let query = PFQuery(className: "Activity")
query.whereKey("postedJob", equalTo: jobPostObject)
let objects = query.findObjects()
print(objects)
我不明白为什么它会在
下面返回此错误'Tried to save an object with a new, unsaved child.'
*** First throw call stack:
(
0 CoreFoundation 0x0000000108213f45 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x0000000107c8bdeb objc_exception_throw + 48
2 CoreFoundation 0x0000000108213e7d +[NSException raise:format:] + 205
3 post 0x00000001063c5e92 -[PFPointerObjectEncoder encodeParseObject:] + 108
4 post 0x00000001063c5324 -[PFEncoder encodeObject:] + 113
5 post 0x00000001063948ef __129+[PFRESTQueryCommand findCommandParametersWithOrder:conditions:selectedKeys:includedKeys:limit:skip:extraOptions:tracingEnabled:]_block_invoke97 + 1808
6 CoreFoundation 0x0000000108180cb5 __65-[__NSDictionaryI enumerateKeysAndObjectsWithOptions:usingBlock:]_block_invoke + 85
7 CoreFoundation 0x0000000108180bbd -[__NSDictionaryI enumerateKeysAndObjectsWithOptions:usingBlock:] + 237
8 post 0x00000001063940fd +[PFRESTQueryCommand findCommandParametersWithOrder:conditions:selectedKeys:includedKeys:limit:skip:extraOptions:tracingEnabled:] + 911
9 post 0x0000000106393d2c +[PFRESTQueryCommand findCommandParametersForQueryState:] + 296
10 post 0x00000001063937df +[PFRESTQueryCommand findCommandForQueryState:withSessionToken:] + 79
11 post 0x00000001063a5739 __78-[PFQueryController findObjectsAsyncForQueryState:withCancellationToken:user:]_block_invoke + 106
12 post 0x000000010634a7be __37+[BFTask taskFromExecutor:withBlock:]_block_invoke + 78
13 post 0x000000010634bf20 __55-[BFTask continueWithExecutor:block:cancellationToken:]_block_invoke_2 + 112
14 libdispatch.dylib 0x000000010a2f1e5d _dispatch_call_block_and_release + 12
15 libdispatch.dylib 0x000000010a31249b _dispatch_client_callout + 8
16 libdispatch.dylib 0x000000010a2fabef _dispatch_root_queue_drain + 1829
17 libdispatch.dylib 0x000000010a2fa4c5 _dispatch_worker_thread3 + 111
18 libsystem_pthread.dylib 0x000000010a65a4f2 _pthread_wqthread + 1129
19 libsystem_pthread.dylib 0x000000010a658375 start_wqthread + 13
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
编辑1：
Import UIKit
class ActivityEmployerVC: UITableViewController {
var num = 0
var postJob: String?
var dataSource: [PFObject] = []
//MARK: - PULL TO REFRESH FUNCTION
func refresh(sender:AnyObject) {
// Updating your data here...
self.fetchDataFromParse()
self.refreshControl?.endRefreshing()
}
override func viewDidLoad() {
super.viewDidLoad()
self.navigationController?.navigationBar.barTintColor = UIColor(netHex: 0x003366)
self.navigationController?.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName: UIColor.whiteColor()]
// Do any additional setup after loading the view.
self.refreshControl?.addTarget(self, action: "refresh:", forControlEvents: UIControlEvents.ValueChanged)
//self.refreshControl?.backgroundColor = UIColor(netHex: 0x003366)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func viewDidAppear(animated: Bool) {
fetchDataFromParse()
}
//MARK: - TABLE VIEW
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
let query = PFQuery(className: "Activity")
let userPointer = PFUser.objectWithoutDataWithObjectId(PFUser.currentUser()?.objectId)
query.whereKey("fromUser", equalTo: userPointer)
let objects = query.findObjects()
self.num = (objects?.count)!
print(num)
return num
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cellIdentifier = "Cells"
let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier , forIndexPath: indexPath)
if dataSource.isEmpty{
fetchDataFromParse()
print("No Post")
} else {
if num == 0{
cell.textLabel?.text = "Start posting a job!"
} else {
//MARK: - TABLEVIEW TITLE CELL
let itemArr:PFObject = self.dataSource[indexPath.row]
postJob = itemArr["type"] as? String
if postJob == "jobPost"{
let jobPostObject = PFObject(className: "JobPost")
let query = PFQuery(className: "Activity")
query.whereKey("postedJob", equalTo: jobPostObject)
let objects = query.findObjects()
print(objects)
cell.textLabel?.text = "You posted a job - \(postJob!)"
}
//MARK: - TABLEVIEW DATE CELL
let createdDate = itemArr.createdAt
let form = NSDateComponentsFormatter()
form.maximumUnitCount = 2
form.unitsStyle = .Abbreviated // or .Full, whatever you prefer
let d = form.stringFromTimeInterval(NSDate.timeIntervalSinceReferenceDate() - createdDate!.timeIntervalSinceReferenceDate)
cell.detailTextLabel?.text = "\(d!) ago"
}//end of if num
}//end of datasource.isempty
return cell
}
//MARK: - DATA FETCHING FUNCTIONS
func fetchDataFromParse() {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), { () -> Void in
//MARK: - CLEARING ARRAYS
self.dataSource.removeAll()
// MARK: - JOB POST QUERY
if PFUser.currentUser()?.objectId == nil{
PFUser.currentUser()?.saveInBackgroundWithBlock({ (success, error) -> Void in
let query = PFQuery(className: "Activity")
//creating a pointer
let userPointer = PFUser.objectWithoutDataWithObjectId(PFUser.currentUser()?.objectId)
query.whereKey("fromUser", equalTo: userPointer)
query.orderByDescending("createdAt")
let objects = query.findObjects()
for object in (objects as? [PFObject])!{
//print(object.objectId)
self.dataSource.append(object)
}//end of for loop
})//end of saveInBackground
} else {
let query = PFQuery(className: "Activity")
//creating a pointer
let userPointer = PFUser.objectWithoutDataWithObjectId(PFUser.currentUser()?.objectId)
query.whereKey("fromUser", equalTo: userPointer)
query.orderByDescending("createdAt")
query.findObjectsInBackgroundWithBlock({ (objs, error) -> Void in
if error == nil {
for obj in (objs as? [PFObject])!{
//print(object.objectId)
self.dataSource.append(obj)
self.tableView.reloadData()
}//for loop
}//end of error == nil
})// end of findobjectsinbackground
print("query executed")
}//end of PFUser objectID == nil else clause
})
}
}
编辑2：
1 个答案:
答案 0 :(得分：1)
这种情况正在发生，因为jobPostObject不是一个完整的对象，它只是一个空的，未保存的JobPost。
查询本身没有多大意义：
首先创建一个新的JobPost
let jobPostObject = PFObject(className: "JobPost")
然后您尝试find与此JobPost相关联的活动：
query.whereKey("postedJob", equalTo: jobPostObject)
由于jobPostObject是全新的，没有数据，更重要的是，从未保存过解析，这个请求怎么能返回任何内容？
这就是说错误：
尝试使用未保存的新子项保存对象
表示您尝试在查询中使用 dirty 的对象。脏对象是新对象，或者是已修改但尚未保存在数据库中的现有对象。
尝试添加
query.includeKey("postedJob")
毕竟你的
let query = PFQuery(className: "Activity")
然后你可以替换jobPostObject部分：
let jobPostObject = PFObject(className: "JobPost")
let query = PFQuery(className: "Activity")
query.whereKey("postedJob", equalTo: jobPostObject)
let objects = query.findObjects()
print(objects)
类似
let jobPostObject = itemArr["postedJob"] as? PFObject
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