NSPredicate BETWEEN with NSDate causes -[__NSDate constantValue]: unrecognized selector sent to instance 0x1e7ff0

匿名 (未验证) 提交于 2019-12-03 01:29:01

问题:

I'm trying to fetch from Core Data records that have a startTime between two dates.

Here's my code:

NSDate *today = [NSDate date]; NSDate *distantFuture = [NSDate distantFuture];  // Create the predicate NSPredicate *predicate = [NSPredicate predicateWithFormat:@"startTime BETWEEN %@", [NSArray arrayWithObjects:today, distantFuture, nil]];  NSLog(@"today: %@, distantFuture: %@", today, distantFuture);    NSLog(@"predicate: %@", predicate);  // Add the predicate to the fetchRequest [[[self fetchedResultsController] fetchRequest] setPredicate:predicate];  NSError *error; if (![[self fetchedResultsController] performFetch:&error])  {     // Update to handle the error appropriately.     NSLog(@"Unresolved error %@, %@", error, [error userInfo]);     exit(-1);  // Fail } 

And here's the console output:

2011-03-11 02:00:03.166 TestApp[2668:307] today: 2011-03-11 01:00:03 AM +0000, distantFuture: 4001-01-01 12:00:00 AM +0000 2011-03-11 02:00:03.174 TestApp[2668:307] predicate: startTime BETWEEN {2011-03-11 01:00:03 AM +0000, 4001-01-01 12:00:00 AM +0000} 2011-03-11 02:00:03.180 TestApp[2668:307] -[__NSDate constantValue]: unrecognized selector sent to instance 0x1e7ff0 2011-03-11 02:00:03.198 TestApp[2668:307] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSDate constantValue]: unrecognized selector sent to instance 0x1e7ff0' *** Call stack at first throw: (     0   CoreFoundation                      0x314d0987 __exceptionPreprocess + 114     1   libobjc.A.dylib                     0x319a149d objc_exception_throw + 24     2   CoreFoundation                      0x314d2133 -[NSObject(NSObject) doesNotRecognizeSelector:] + 102     3   CoreFoundation                      0x31479aa9 ___forwarding___ + 508     4   CoreFoundation                      0x31479860 _CF_forwarding_prep_0 + 48     5   CoreData                            0x352ed973 -[NSSQLSimpleWhereIntermediate _generateSQLBetweenStringInContext:] + 766     6   CoreData                            0x35244fff -[NSSQLSimpleWhereIntermediate generateSQLStringInContext:] + 502     7   CoreData                            0x35244647 -[NSSQLFetchIntermediate generateSQLStringInContext:] + 74     8   CoreData                            0x352e42b3 -[NSSQLGenerator newSQLStatementForFetchRequest:ignoreInheritance:countOnly:nestingLevel:] + 234     9   CoreData                            0x352414ab -[NSSQLAdapter _newSelectStatementWithFetchRequest:ignoreInheritance:] + 378     10  CoreData                            0x35241329 -[NSSQLAdapter newSelectStatementWithFetchRequest:] + 16     11  CoreData                            0x35241205 -[NSSQLCore newRowsForFetchPlan:] + 288     12  CoreData                            0x35240531 -[NSSQLCore objectsForFetchRequest:inContext:] + 420     13  CoreData                            0x35240151 -[NSSQLCore executeRequest:withContext:error:] + 304     14  CoreData                            0x352d0295 -[NSPersistentStoreCoordinator executeRequest:withContext:error:] + 896     15  CoreData                            0x3523d877 -[NSManagedObjectContext executeFetchRequest:error:] + 374     16  CoreData                            0x352f541b -[NSFetchedResultsController performFetch:] + 766     17  TestApp                             0x0001ac6d -[MatchesCalendarDataSource loadMatchesFrom:to:delegate:] + 268     18  TestApp                             0x0001ad51 -[MatchesCalendarDataSource presentingDatesFrom:to:delegate:] + 68     19  TestApp                             0x00021353 -[KalViewController reloadData] + 110     20  TestApp                             0x00021b15 -[KalViewController loadView] + 452     21  UIKit                               0x338dc227 -[UIViewController view] + 30     22  UIKit                               0x338e8d0b -[UIViewController contentScrollView] + 22     23  UIKit                               0x338e8b7b -[UINavigationController _computeAndApplyScrollContentInsetDeltaForViewController:] + 30     24  UIKit                               0x338e8a79 -[UINavigationController _layoutViewController:] + 24     25  UIKit                               0x338e84d3 -[UINavigationController _startTransition:fromViewController:toViewController:] + 254     26  UIKit                               0x338e835f -[UINavigationController _startDeferredTransitionIfNeeded] + 182     27  UIKit                               0x338e82a3 -[UINavigationController viewWillLayoutSubviews] + 14     28  UIKit                               0x338e823f -[UILayoutContainerView layoutSubviews] + 138     29  UIKit                               0x338b10cf -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 26     30  CoreFoundation                      0x3146ebbf -[NSObject(NSObject) performSelector:withObject:] + 22     31  QuartzCore                          0x30a6c685 -[CALayer layoutSublayers] + 120     32  QuartzCore                          0x30a6c43d CALayerLayoutIfNeeded + 184     33  QuartzCore                          0x30a6656d _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 212     34  QuartzCore                          0x30a66383 _ZN2CA11Transaction6commitEv + 190     35  QuartzCore                          0x30a89f9d _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 52     36  CoreFoundation                      0x31460c59 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 16     37  CoreFoundation                      0x31460acd __CFRunLoopDoObservers + 412     38  CoreFoundation                      0x314580cb __CFRunLoopRun + 854     39  CoreFoundation                      0x31457c87 CFRunLoopRunSpecific + 230     40  CoreFoundation                      0x31457b8f CFRunLoopRunInMode + 58     41  GraphicsServices                    0x35d664ab GSEventRunModal + 114     42  GraphicsServices                    0x35d66557 GSEventRun + 62     43  UIKit                               0x338d5329 -[UIApplication _run] + 412     44  UIKit                               0x338d2e93 UIApplicationMain + 670     45  TestApp                             0x000029d7 main + 70     46  TestApp                             0x00002958 start + 52 ) terminate called after throwing an instance of 'NSException' 

I've also tried the predicate below, which uses >= AND

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(startTime >= %@) AND (startTime 

As a test I've tried a predicate that doesn't include NSDate objects and it works fine (see below):

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"location.title == %@", @"Boston"]; 

Any help or advice would be much appreciated.

Many thanks, Matthew


Edit

Thanks for your help Dave.

So now I'm back to using the construct but I'm getting 0 objects fetched.

I was just using today and distantFuture as a test to make absolutely sure that my startTime would be between those dates. In the real code it's a range from fromDate to toDate.

Here's my NSPredicate:

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"( ( %@ 

Here's the console output:

predicate: CAST(336261600.000000, "NSDate") 

Here are the dates that are in Core Data (the Attribute Type is set to Date):

startTime --------- 337249800 337309200 337318200 

I have no idea why 0 objects are returned. Can anyone see where I'm going wrong?

回答1:

Perhaps try using AND instead of && (although your console output seems to show it converting correctly.

I just posted an example that works for me, note that my condition is flipped like so:

@"(%K >= %@) AND (%K

Here is the full example



回答2:

According to the documentation, the BETWEEN operator counts as an aggregate expression, and ...

Aggregate expressions are not supported by Core Data.

So yes, in order to work around this, you must use the >= and construction.

However, given that one of your dates is [NSDate distantFuture], you don't need the "less than" comparison at all. You should be able to do:

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"startTime >= %@", [NSDate date]]; 


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