我收到一个运行时错误消息：
无效的提取请求：在没有GROUP BY且userInfo为（null）的情况下
在我的代码中显示“ // error here”的地方：
let request = NSFetchRequest<NSFetchRequestResult>(entityName: CoreDataStrings.entityAffirmation)
let predicate = NSPredicate(format:"recordName == %@", privateRecord.recordID.recordName)
request.havingPredicate = predicate
print("predicte =", predicate)
do {
let affirmationEntityInstances: [Affirmation] = try managedObjectContext.fetch(request) as! [Affirmation] // error here
print("result =", affirmationEntityInstances)
...
} catch {
...
}
代码永远不会到达带有注释“ // error here”的行之后的打印语句。该错误不是catch语句捕获的错误。
这是从打印语句开始打印谓词的调试窗口的结果。
predicte = recordName == "F9DB2EE8-B693-44B7-BA2B-3EAB689A9940"
2019-07-17 14:05:50.409279-0500 Affirmations[68672:14476409] [error] error: SQLCore dispatchRequest: exception handling request: <NSSQLFetchRequestContext: 0x6000019402a0> , Invalid fetch request: HAVING with no GROUP BY with userInfo of (null)
CoreData: error: SQLCore dispatchRequest: exception handling request: <NSSQLFetchRequestContext: 0x6000019402a0> , Invalid fetch request: HAVING with no GROUP BY with userInfo of (null)
2019-07-17 14:05:50.625355-0500 Affirmations[68672:14476409] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Invalid fetch request: HAVING with no GROUP BY'
*** First throw call stack:
(
0 CoreFoundation 0x000000010fb596fb __exceptionPreprocess + 331
1 libobjc.A.dylib 0x000000010eb7cac5 objc_exception_throw + 48
2 CoreData 0x000000010f61aeb0 -[NSSQLGenerator newSQLStatementForRequest:ignoreInheritance:countOnly:nestingLevel:nestIsWhereScoped:requestContext:] + 1584
3 CoreData 0x000000010f62549e -[NSSQLiteAdapter _statementForFetchRequestContext:ignoreInheritance:countOnly:nestingLevel:] + 142
4 CoreData 0x000000010f4d32e4 -[NSSQLiteAdapter newSelectStatementWithFetchRequestContext:ignoreInheritance:] + 116
5 CoreData 0x000000010f670843 -[NSSQLFetchRequestContext _createStatement] + 67
6 CoreData 0x000000010f6707de -[NSSQLFetchRequestContext fetchStatement] + 142
7 CoreData 0x000000010f6717cb -[NSSQLFetchRequestContext executeRequestCore:] + 27
8 CoreData 0x000000010f6db010 -[NSSQLStoreRequestContext executeRequestUsingConnection:] + 208
9 CoreData 0x000000010f6af9eb __52-[NSSQLDefaultConnectionManager handleStoreRequest:]_block_invoke + 75
10 libdispatch.dylib 0x0000000111cb1db5 _dispatch_client_callout + 8
11 libdispatch.dylib 0x0000000111cbfd08 _dispatch_lane_barrier_sync_invoke_and_complete + 132
12 CoreData 0x000000010f6af8d0 -[NSSQLDefaultConnectionManager handleStoreRequest:] + 336
13 CoreData 0x000000010f6b7504 -[NSSQLCoreDispatchManager routeStoreRequest:] + 308
14 CoreData 0x000000010f5ffc38 -[NSSQLCore dispatchRequest:withRetries:] + 232
15 CoreData 0x000000010f5fc9ad -[NSSQLCore processFetchRequest:inContext:] + 93
16 CoreData 0x000000010f4d27ee -[NSSQLCore executeRequest:withContext:error:] + 574
17 CoreData 0x000000010f5e1007 __65-[NSPersistentStoreCoordinator executeRequest:withContext:error:]_block_invoke + 2039
18 CoreData 0x000000010f5d9220 -[NSPersistentStoreCoordinator _routeHeavyweightBlock:] + 288
19 CoreData 0x000000010f4d1fc0 -[NSPersistentStoreCoordinator executeRequest:withContext:error:] + 1296
20 CoreData 0x000000010f4d0295 -[NSManagedObjectContext executeFetchRequest:error:] + 933
21 Affirmations 0x000000010dfd8230 $s12Affirmations14UTIAffirmationC6recordACSo8CKRecordC_tcfc + 13072
22 Affirmations 0x000000010dfd4f10 $s12Affirmations14UTIAffirmationC6recordACSo8CKRecordC_tcfC + 64
23 Affirmations 0x000000010df95584 $s12Affirmations25initDataModelFromCloudKityyFyycfU_ySaySo8CKRecordCGSg_s5Error_pSgtcfU_ + 1252
24 Affirmations 0x000000010df8fde6 $sSaySo8CKRecordCGSgs5Error_pSgIeggg_So7NSArrayCSgSo7NSErrorCSgIeyByy_TR + 230
25 CloudKit 0x000000010e3cbb0d -[CKQueryOperation _finishOnCallbackQueueWithError:] + 613
26 CloudKit 0x000000010e3c4c1a -[CKOperation _finishInternalOnCallbackQueueWithError:] + 582
27 CloudKit 0x000000010e3c49ba -[CKOperation _handleCompletionCallback:] + 148
28 CloudKit 0x000000010e3cb7e1 -[CKQueryOperation _handleCompletionCallback:] + 197
29 CloudKit 0x000000010e43a6c5 __68-[CKOperationCallbackManager _performCallbackForOperation:callback:]_block_invoke + 278
30 libdispatch.dylib 0x0000000111cbf725 _dispatch_block_async_invoke2 + 83
31 libdispatch.dylib 0x0000000111cb1db5 _dispatch_client_callout + 8
32 libdispatch.dylib 0x0000000111cb9225 _dispatch_lane_serial_drain + 778
33 libdispatch.dylib 0x0000000111cb9ed0 _dispatch_lane_invoke + 477
34 libdispatch.dylib 0x0000000111cc3ea3 _dispatch_workloop_worker_thread + 733
35 libsystem_pthread.dylib 0x000000011209a611 _pthread_wqthread + 421
36 libsystem_pthread.dylib 0x000000011209a3fd start_wqthread + 13
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
这是我的NSManagedObject的子类：
public class Affirmation: NSManagedObject {
}
extension Affirmation {
@nonobjc public class func fetchRequest() -> NSFetchRequest<Affirmation> {
return NSFetchRequest<Affirmation>(entityName: "Affirmation")
}
@NSManaged public var body: String
@NSManaged public var count: Int64
@NSManaged public var days: NSData
@NSManaged public var frequency: Int64
@NSManaged public var notificationIdentifiers: NSObject
@NSManaged public var recordName: String?
@NSManaged public var time: NSDate
@NSManaged public var timestamp: NSDate
@NSManaged public var title: String
}
答案 0 :(得分：1)
您正在使用不带GROUP BY指令的标准查询-这就是错误所在-因此请使用标准API
request.predicate = predicate
如果您指定请求的通用类型，就可以摆脱类型转换和类型注释
let request = NSFetchRequest<Affirmation>(entityName: CoreDataStrings.entityAffirmation)
...
let affirmationEntityInstances = try managedObjectContext.fetch(request)