[英]Core data - data fault
我正在將數據保存到核心數據,更新,刪除等。關於核心數據和保存,我一點都沒有錯誤。 但是,當我嘗試打開sqlite數據庫文件時,那里什么也沒有,也沒有更新並保存到核心數據。
AppDelegate中:
- (void)saveContext
{
NSError *error = nil;
NSManagedObjectContext *managedObjectContext = self.managedObjectContext;
if (managedObjectContext != nil) {
if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
}
}
// Returns the managed object context for the application.
// If the context doesn't already exist, it is created and bound to the persistent store coordinator for the application.
- (NSManagedObjectContext *)managedObjectContext
{
if (_managedObjectContext != nil) {
return _managedObjectContext;
}
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil) {
_managedObjectContext = [[NSManagedObjectContext alloc] init];
[_managedObjectContext setPersistentStoreCoordinator:coordinator];
}
return _managedObjectContext;
}
// Returns the managed object model for the application.
// If the model doesn't already exist, it is created from the application's model.
- (NSManagedObjectModel *)managedObjectModel
{
if (_managedObjectModel != nil) {
return _managedObjectModel;
}
NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"CoreDataModel" withExtension:@"momd"];
_managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
return _managedObjectModel;
}
// Returns the persistent store coordinator for the application.
// If the coordinator doesn't already exist, it is created and the application's store added to it.
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
if (_persistentStoreCoordinator != nil) {
return _persistentStoreCoordinator;
}
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"CoreDataModel.sqlite"];
NSError *error = nil;
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
return _persistentStoreCoordinator;
}
#pragma mark - Application's Documents directory
// Returns the URL to the application's Documents directory.
- (NSURL *)applicationDocumentsDirectory
{
return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}
更新核心數據的示例:
- (void)enableORdisableAlertInDatabase:(FMDatabase*)database andOperation:(int)operation andTrapID:(int)trapID
{
NSLog(@"%s", __PRETTY_FUNCTION__);
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:kCORE_DATA_TRAP_ENTITY inManagedObjectContext:appDelegate.managedObjectContext];
[fetchRequest setEntity:entity];
// Specify criteria for filtering which objects to fetch
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"trapID==%i", trapID];
[fetchRequest setPredicate:predicate];
NSError *error = nil;
NSArray *fetchedObjects = [appDelegate.managedObjectContext executeFetchRequest:fetchRequest error:&error];
if (fetchedObjects == nil) {
NSLog(@"%s error: %@", __PRETTY_FUNCTION__, error.localizedDescription);
}
else {
CoreDataTrap *trap = (CoreDataTrap*)fetchedObjects.firstObject;
[trap setAlert:[NSNumber numberWithInt:operation]];
[appDelegate.managedObjectContext save:&error];
if (error != nil) {
NSLog(@"enableORdisableAlertInDatabase Error: %@", error.localizedDescription);
}
}
}
編輯:這是添加或更新對象的功能:
- (void)addOrUpdateTrap:(Traps*)trapObject
{
int trapID = trapObject.getTrapID;
CoreDataTrap *trapEntity = nil;
NSError *error = nil;
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:@"CoreDataTrap"];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"trapID == %d", trapID];
[fetchRequest setPredicate:predicate];
NSArray *results = [appDelegate.managedObjectContext executeFetchRequest:fetchRequest error:&error];
if (results == nil)
{
// Handle error
}
else if ([results count] == 0)
{
// Nothing to update, add new trap
// Create a new record (row)
trapEntity = [NSEntityDescription insertNewObjectForEntityForName:@"CoreDataTrap" inManagedObjectContext:appDelegate.managedObjectContext];
}
else
{
trapEntity = results[0]; // There should be only one object for the ID.
}
if (trapEntity != nil)
{
// Set properties for new or existing object ...
// Int
[trapEntity setTrapID:[NSNumber numberWithInt:trapObject.getTrapID]];
[trapEntity setType:[NSNumber numberWithInt:trapObject.getTrapType]];
[trapEntity setDist:[NSNumber numberWithInt:trapObject.getTrapDistanceToCar]];
[trapEntity setDist_to_close_point:[NSNumber numberWithInt:trapObject.getTrapDistanceToClosePoint]];
[trapEntity setActive:[NSNumber numberWithInt:trapObject.isActive]];
[trapEntity setAlert:[NSNumber numberWithInt:trapObject.isAlert]];
[trapEntity setAlarmDistance:[NSNumber numberWithInt:trapObject.alarmDistance]];
[trapEntity setRoadNumber:[NSNumber numberWithInt:trapObject.roadNumber]];
[trapEntity setPolys:[NSNumber numberWithInt:trapObject.polygons]];
[trapEntity setEnter_to_area:[NSNumber numberWithInt:trapObject.getTrapEnterToArea]];
// Double
[trapEntity setLat:[NSNumber numberWithDouble:trapObject.getTrapLat]];
[trapEntity setLon:[NSNumber numberWithDouble:trapObject.getTrapLon]];
[trapEntity setClose_point_lat:[NSNumber numberWithDouble:trapObject.getTrapClosePointLat]];
[trapEntity setClose_point_lon:[NSNumber numberWithDouble:trapObject.getTrapClosePointLon]];
// NSString
[trapEntity setLastTrapAlarm:[NSString stringWithFormat:@"%li", trapObject.getTrapLastAlarm]];
[trapEntity setPoly0:trapObject.getTrapPolygonA];
[trapEntity setPoly1: trapObject.getTrapPolygonB];
[trapEntity setPoly2: trapObject.getTrapPolygonC];
[trapEntity setPolygonAzimut1: trapObject.getTrapPolygonAzimuthA];
[trapEntity setPolygonAzimut2: trapObject.getTrapPolygonAzimuthB];
[trapEntity setPolygonAzimut3: trapObject.getTrapPolygonAzimuthC];
[trapEntity setDesc: trapObject.getTrapDesc];
// etc. for all properties ...
error = nil;
if (![appDelegate.managedObjectContext save:&error])
{
NSLog(@"%s error: %@", __PRETTY_FUNCTION__, error.localizedDescription);
}
}
}
更新-1:我記錄了對象並得到了(將它們添加到核心數據時):
"<CoreDataTrap: 0x147c4140> (entity: CoreDataTrap; id: 0x1477d510 <x-coredata://CD85E666-FA17-4D5F-A221-9BC962C7667B/CoreDataTrap/p11> ; data: <fault>)",
"<CoreDataTrap: 0x147c4240> (entity: CoreDataTrap; id: 0x1477d520 <x-coredata://CD85E666-FA17-4D5F-A221-9BC962C7667B/CoreDataTrap/p12> ; data: <fault>)",
"<CoreDataTrap: 0x145507d0> (entity: CoreDataTrap; id: 0x147cd410 <x-coredata://CD85E666-FA17-4D5F-A221-9BC962C7667B/CoreDataTrap/p13> ; data: <fault>)",
"<CoreDataTrap: 0x14550900> (entity: CoreDataTrap; id: 0x147cd420 <x-coredata://CD85E666-FA17-4D5F-A221-9BC962C7667B/CoreDataTrap/p14> ; data: <fault>)",
"<CoreDataTrap: 0x14550a30> (entity: CoreDataTrap; id: 0x147cd430 <x-coredata://CD85E666-FA17-4D5F-A221-9BC962C7667B/CoreDataTrap/p15> ; data: <fault>)",
"<CoreDataTrap: 0x145401b0> (entity: CoreDataTrap; id: 0x147cd440 <x-coredata://CD85E666-FA17-4D5F-A221-9BC962C7667B/CoreDataTrap/p16> ; data: <fault>)",
"<CoreDataTrap: 0x145402b0> (entity: CoreDataTrap; id: 0x147cd450 <x-coredata://CD85E666-FA17-4D5F-A221-9BC962C7667B/CoreDataTrap/p17> ; data: <fault>)",
"<CoreDataTrap: 0x14540440> (entity: CoreDataTrap; id: 0x147cd460 <x-coredata://CD85E666-FA17-4D5F-A221-9BC962C7667B/CoreDataTrap/p18> ; data: <fault>)",
"<CoreDataTrap: 0x1453e380> (entity: CoreDataTrap; id: 0x147cd470 <x-coredata://CD85E666-FA17-4D5F-A221-9BC962C7667B/CoreDataTrap/p19> ; data: <fault>)",
"<CoreDataTrap: 0x1453e480> (entity: CoreDataTrap; id: 0x147cd480 <x-coredata://CD85E666-FA17-4D5F-A221-9BC962C7667B/CoreDataTrap/p20> ; data: <fault>)"
而且我還記錄了它們的值,它似乎是正確的值。
仍然,它沒有更新。
您如何知道數據不在SQLite中? 您正在查看文件還是在屏幕上看不到數據。 那里有兩個不同的潛在問題。
如果您正在查看文件,並且使用的是iOS 7,則可能是因為日志記錄是您混淆的根源。 日志模式在iOS7中已打開,將導致更新在二級文件中保留一段時間。 這將使您看起來數據不在SQLite文件中,因為它們尚未從日志文件移到SQLite文件中。 在這種情況下,一切都很好。
如果您正在尋找要在視圖中顯示的數據,則可能是您的視圖代碼有問題。 發布該視圖代碼將有助於對其進行診斷。
我懷疑您正在查看SQLite文件。 如果我錯了,請糾正我。
順便說一句,這:
[appDelegate.managedObjectContext save:&error];
if (error != nil) {
NSLog(@"enableORdisableAlertInDatabase Error: %@", error.localizedDescription);
}
檢查此錯誤的不好方法。 -save:
返回一個布爾值,應咨詢該錯誤:
if ([[appDelegate managedObjectContext] save:&error] == NO) {
NSLog(@"Error saving: %@\n%@", [error localizedDescription], [error userInfo]);
}
使用最新版本的Base或SQLite Professional檢查您的數據庫,就可以了。
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