无法将sqlite文件从应用程序捆绑包复制到文档目录：正在获取（可可错误260）

Question

I am trying to copy my sqlite file from app bundle into documents directory using the code below

-(id)init {

    self = [super init];
    if (self) {

// 1. Create a handle to the database file for UIManagedDocument

        NSURL *docURL = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
        docURL = [docURL URLByAppendingPathComponent:@"DefaultDatabase"];
        self.document =  [[UIManagedDocument alloc] initWithFileURL:docURL]; // URL of the location of document i.e. /documents directory
    NSLog(@" URL document");

        //set our document up for automatic migrations

        if (self.document) {
            NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
                                 [NSNumber numberWithBool:YES],
            NSMigratePersistentStoresAutomaticallyOption,
                                 [NSNumber numberWithBool:YES],
            NSInferMappingModelAutomaticallyOption, nil];

            self.document.persistentStoreOptions = options;

            // Register for Notifications

            [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(objectsDidChange:) name:NSManagedObjectContextObjectsDidChangeNotification object:self.document.managedObjectContext];

            [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(contextDidSave:) name:NSManagedObjectContextDidSaveNotification object:self.document.managedObjectContext];
        } else {         
            NSLog(@"The UIManaged Document could not be initialized");

        }

// 2. Check if the persistent store file does not exists in case of first run

    if (!([[NSFileManager defaultManager] fileExistsAtPath:[self.document.fileURL path]])) {
        NSLog(@" persistent file not found trying to copy from app bbundle");
        NSString *docFileName = [UIManagedDocument persistentStoreName];
        NSString *docFilePath = [[NSBundle mainBundle] pathForResource:docFileName ofType:@"sqlite"];
        **NSLog(@" doc file path = %@", docFilePath);**
        if (docFilePath) { // found the database file in app bundle
            NSLog(@" found file in bundle");
            //Production: Copy from app bundle.
            NSError *error = nil;
            NSArray *searchPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
            NSString *copyToPath  = [searchPaths lastObject];
            if([[NSFileManager defaultManager] copyItemAtPath:docFilePath toPath:copyToPath error:&error]){
                NSLog(@"File successfully copied");
            } else { // if could not locate the file
                [[[UIAlertView alloc]initWithTitle:NSLocalizedString(@"error", nil) message: NSLocalizedString(@"failedcopydb", nil)  delegate:nil cancelButtonTitle:NSLocalizedString(@"ok", nil)  otherButtonTitles:nil] show];
                NSLog(@"Error description-%@ \n", [error localizedDescription]);
                NSLog(@"Error reason-%@", [error localizedFailureReason]);
            }
        }
    }
}
return self;

}

a) I created the .sqlite file using data loader app which uses UIManagedDcoument to add data to Core Data. The .sqlite file gets generated in documents directory.

b) I add the *.sqlite file to resources folder and add it to bundle. If I check the app bundle using Terminal..I see 'persistent store' and <app name.momd> file under the bundle directory. There is no file with extension .sqlite

c)But in my code above when I check for whether files exists in app bundle using line of code, it is successful. So file exists in bundle

   NSString *file = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:fileName];

d) But when try to copy, it fails and gives me (Cocca Error 206) meaning its unable to find the .sqlite file in the app bundle.

  if([[NSFileManager defaultManager] copyItemAtPath:file toPath:copyToPath error:&error])

which is in line with the fact that I don't see .sqlite file under app bundle directory instead I see a persistent store and .momd files.

So where I am going wrong ?

EDIT

This is an explanation of how I am generating my mydata.sqlite file.

I am using Core Data and want to provide a pre-poulated database upon first launch of app to the user. So I used a data loader app to create .sqlite file for me. I am using UIManagedDocument for core data. After I run the app, I see a mydata.sqlite directory gets created under documents directory. The directory structure is as follows

/users//.../documents/mydata.sqlite/storeContent/persistenStore.

So basically instead of creating a file, it creates a directory with .sqlite extension and I see persistentStore file. So when I try to copy resources under app bundle in target under build phases..it adds the persistentStore and not .sqlite file.

My question whatever is described is correct and I am supposed to handle it differently in my code. If yes, what is that I am supposed to do to get handle on data store.

I thought .sqlite was a file and not a directory. Please guide

Thanks

Answer 1

This line does not actually check if the file exists:

NSString *file = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:fileName];

All that does is build the path in file . If you want to check whether it exists, you need to use [NSFileManager fileExistsAtPath:] . Or you could go back to using pathForResource:ofType: , which was apparently correct when it returned nil .

You don't seem to be copying the file into the bundle at all. This is a problem with your Xcode project configuration.

Answer 2

I read up apple documentation on UIManagedDocument and here are the key points that I was going wrong on

1. Was handling UIManagedDocument incorrectly. When you initialize a managed document, you specify the URL for the document location. and not the document itself. If you need to add

2. You can perform additional customization by creating a subclass of UIManagedDocument ie Override persistentStoreName to customize the name of the persistent store file inside the document's file package.

3. cutting and pasting the example code for the right way to handle the data file

You create a managed document object using initWithFileURL:; if you want, you can then configure the document before you use its managed object context. Typically you might set the persistent store options, as illustrated in this example:

NSURL *docURL = [[self applicationDocumentsDirectory]        URLByAppendingPathComponent:@"FirstDocument"];
 doc = [[UIManagedDocument alloc] initWithFileURL:docURL];

NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
 [NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
 [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];
doc.persistentStoreOptions = options;


**if ([[NSFileManager defaultManager] fileExistsAtPath:[docURL path]]**) {
   [doc openWithCompletionHandler:^(BOOL success){
    if (!success) {
        // Handle the error.
    }
    }];
 }
  else {
   [self addInitialData];
   [doc saveToURL:docURL forSaveOperation:UIDocumentSaveForCreating completionHandler:^(BOOL success){
      if (!success) {
        // Handle the error.
     }
     }];
    }