Question

插入Core Data突然停止工作。我使用以下代码设置了persistentStoreCoordinator。请注意，url为Spot.sqlite。

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
    if (_persistentStoreCoordinator != nil) {
        return _persistentStoreCoordinator;
    }

    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"Spot.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;
}

我运行应用程序，然后执行

cd ~/Library/Application Support/iPhone Simulator/7.0/Applications
find . -name MyAppName
A1DF7916-AE39-4367-BFD2-22A8BAA2AFD2
cd A1DF7916-AE39-4367-BFD2-22A8BAA2AFD2/Documents
ls 
(results) Spot.sqlite                       Spot.sqlite-shm                   Spot.sqlite-wal
sqlite3 Spot.sqlite
sqlite> .tables
ZMYCATEGORY   Z_METADATA    Z_PRIMARYKEY
sqlite> select * from ZMYCATEGORY;

并且没有显示任何结果，但是当我选择Z_METADATA的内容时，我确实得到一行输出。

这是我用来在托管对象上下文中插入对象的代码：

+ (void)insertParentCategoriesIntoCoreDataFromArray:(NSArray *)array {
    ROAppDelegate *delegate = (ROAppDelegate *)[UIApplication sharedApplication].delegate;
    NSManagedObjectContext *managedObjectContext = [delegate managedObjectContext];

    NSEntityDescription *categoryEntity = [NSEntityDescription entityForName:@"ROCategory" inManagedObjectContext:managedObjectContext];

    for (int i = 0; i < [array count]; i++) {
        ROCategory *category = [[ROCategory alloc] initWithEntity:categoryEntity insertIntoManagedObjectContext:managedObjectContext];
        NSArray *mySQLRow = [array objectAtIndex:i];
        NSString *name = [mySQLRow objectAtIndex:1];
        [category setValue:name forKey:@"name"];
    }
}

当我单步执行此代码时，它会按照我的预期执行。没有错误发生。然而相关的sqlite表仍然是空的，当我运行以下代码时，我得到一个空的结果集。

            ...
            NSFetchRequest *request = [[NSFetchRequest alloc] init];
            request.predicate = [NSPredicate predicateWithFormat:[NSString stringWithFormat:@"name ==[c] \'%@\'", key]]; // the [c] means case-sensitive
            [request setEntity:categoryEntity];

            NSError *error;
            fetchedObjects = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy];

Answer 1

我忘记了save。

我包含了这段代码并且有效：

NSError *error = nil;
if (![[((ROAppDelegate *)[UIApplication sharedApplication].delegate) managedObjectContext] save:&error]) {
    // error                                         
}

未插入CoreData对象

1 个答案: