如何禁用WAL日志模式

Question

https://developer.apple.com/library/ios/releasenotes/DataManagement/WhatsNew_CoreData_iOS/

我在禁用日记模式时遇到问题.

我的代码是:

static NSManagedObjectContext *managedObjectContext(){
static NSManagedObjectContext *context = nil;
if (context != nil) {
    return context;
}

NSString * const NSSQLitePragmasOption;

NSSQLitePragmasOption : @{ @"journal_mode" : @"DELETE" };


@autoreleasepool {
    context = [[NSManagedObjectContext alloc] init];

    NSPersistentStoreCoordinator *coordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:managedObjectModel()];
    [context setPersistentStoreCoordinator:coordinator];

    NSString *STORE_TYPE = NSSQLiteStoreType;

    NSString *path = @"ExerciseDB";
    NSURL *url = [NSURL fileURLWithPath:[path stringByAppendingPathExtension:@"sqlite"]];





    NSError *error;
    NSPersistentStore *newStore = [coordinator addPersistentStoreWithType:STORE_TYPE configuration:nil URL:url options:NSSQLitePragmasOption error:&error];

    if (newStore == nil) {
        NSLog(@"Store Configuration Failure %@", ([error localizedDescription] != nil) ? [error localizedDescription] : @"Unknown Error");
    }
}
return context;
}

我将如何禁用日记模式WAL.

谢谢

Answer 1

要禁用WAL模式,请将journal_mode设置为DELETE

NSMutableDictionary *pragmaOptions = [NSMutableDictionary dictionary];
[pragmaOptions setObject:@"DELETE" forKey:@"journal_mode"];

NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, pragmaOptions, NSSQLitePragmasOption, nil];
[_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:options error:&error]

Answer 2

来自Apple技术文档:技术问答QA1809

NSDictionary *options = @{NSSQLitePragmasOption:@{@"journal_mode":@"DELETE"}};
if (! [persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType
                                            configuration:nil
                                            URL:storeURL
                                            options:options
                                            error:&error]) {
    // error handling.
}