Cocoa Error: 516 while making writable copy of the SQLite database

Question

I'm doing a small database driven app. I have my SQLite db file under Supporting Files in xcode. At first I was trying to write data to it when it was in the mainbundle but couldn't. After searching, I came across this answer and I changed my code to the following.

- (void)viewDidLoad
{
    [super viewDidLoad];

        BOOL success;
        NSFileManager *filemngr = [[NSFileManager alloc] init];
        NSError *error;
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);
        NSString *documentDirectory = [paths objectAtIndex:0];
        NSString *writableDbPath = [documentDirectory stringByAppendingPathComponent:@"contacts.sqlite"];
        success = [filemngr fileExistsAtPath:writableDbPath];
        if(!success)
        {
            [status setText:@"Error occurred!"];
        }

        NSString *defaultDbPath = [[[NSBundle mainBundle] resourcePath]stringByAppendingPathComponent:@"contacts.sqlite"];
        success = [filemngr copyItemAtPath:defaultDbPath toPath:writableDbPath error:&error];
        if (!success)
        {
            [status setText:[error localizedDescription]];
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error!"
                                                            message:[error localizedDescription]
                                                           delegate:nil
                                                  cancelButtonTitle:@"OK"
                                                  otherButtonTitles:nil];
            [alert show];
        }
    }

I get the following error in the final if block when I'm trying to copy the file to the writable location (where the UIAlertView is shown).

The operation couldn't be completed. (Cocoa error 516)

Can anyone please tell me how to correct this error?

Thank you.

score 3 · Accepted Answer · answered Dec 19 '12 at 10:58

You want to copy the file to document directory if it is not already copied to there. In your code if the file is already there then also you are trying to copy it to the document directory. That'll result in the execution of second if(!success) block. Change your method like:

- (void)viewDidLoad
{
    [super viewDidLoad];

        BOOL success;
        NSFileManager *filemngr = [[NSFileManager alloc] init];
        NSError *error;
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);
        NSString *documentDirectory = [paths objectAtIndex:0];
        NSString *writableDbPath = [documentDirectory stringByAppendingPathComponent:@"contacts.sqlite"];
        success = [filemngr fileExistsAtPath:writableDbPath];
        if(!success)
        {
            NSString *defaultDbPath = [[[NSBundle mainBundle] resourcePath]stringByAppendingPathComponent:@"contacts.sqlite"];
        success = [filemngr copyItemAtPath:defaultDbPath toPath:writableDbPath error:&error];
          if (!success)
          {
            [status setText:[error localizedDescription]];
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error!"
                                                            message:[error localizedDescription]
                                                           delegate:nil
                                                  cancelButtonTitle:@"OK"
                                                  otherButtonTitles:nil];
            [alert show];
          }
        }
    }

Thank you very much Midhun. This error is gone but I have one other small issue. Now in my .h file, I have a reference to my database path like this `NSString *databasePath`. In my .m file where I save data to the DB, I retrieve that value like this. `const chat *dbpath = [databasePath UTF8String]`. Do I have to assign the new `writableDbPath` value to that? Because My saving data doesn't work now. I tried this `databasePath = writableDbPath` in the `viewDidLoad` method but that didn't work. What should I do? Thanks again :) — Isuru, Dec 19 '12 at 11:22
@Isuru: your databasePath should be the path in document directory. You need to assign the path when you use it — Midhun MP, Dec 19 '12 at 11:27

Cocoa Error: 516 while making writable copy of the SQLite database

1 Answers1