无法在 iOS 中打开/创建 SQLite 数据库

我有 2 个文件 DatabaseViewController.h 文件，其中有

#import <UIKit/UIKit.h>
#import "sqlite3.h"

@interface DatabaseViewController : UIViewController
@property (weak, nonatomic) IBOutlet UILabel *status;
@property(strong,nonatomic) NSString *databasePath;
@property(nonatomic) sqlite3 *contactDb;

@end

另一个数据库ViewController.m：

- (void)viewDidLoad
{

[super viewDidLoad];
NSString *docsDir;
NSArray *dirPaths;

// Get the documents directory

dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSUserDomainMask, YES);
docsDir = dirPaths[0];

//Buid the path for database file
_databasePath = [[NSString alloc]
                 initWithString:[docsDir stringByAppendingPathComponent:@"contacts.db"]];

NSFileManager *filemgr = [NSFileManager defaultManager];

if([filemgr fileExistsAtPath: _databasePath ] == NO)
{
    const char *db_path = [_databasePath UTF8String];

    if(sqlite3_open(db_path, &_contactDb) == SQLITE_OK)
    {
        char *errMsg;
        const char *sql_stmt =
        "CREATE TABLE IF NOT EXISTS CONTACTS (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, ADDRESS TEXT, PHONE TEXT)";

        if (sqlite3_exec(_contactDb, sql_stmt, NULL, NULL, &errMsg) != SQLITE_OK)
        {
            _status.text = @"Failed to create table";
        }
        sqlite3_close(_contactDb);
    } else {

        _status.text = @"Failed to open/create database";
    }
}


}

不幸的是，声明

if(sqlite3_open(db_path, &_contactDb) == SQLITE_OK)

永远不会成功。

它只是路由到

 _status.text = @"Failed to open/create database";

问题是什么？

我确实将 libsqlite3.dylib 添加到项目中。我正在使用 Xcode 4.5。

参考NSDocumentationDirectory应该NSDocumentDirectory.