无法将sqlite数据库从app的mainbundle复制到用户文档

Question

I can't copy my sqlite database to the users documents folder, the database has always 0 byte but should have 322 kb.

I have also checked that the database is included in the target membership.

The Problem is that i can't copy the database correctly.

Here is my code:

-(void)initDatabase
{
// Create a string containing the full path to the sqlite.db inside the documents folder
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *databasePath = [documentsDirectory stringByAppendingPathComponent:@"wine.sqlite"];

// Check to see if the database file already exists
bool databaseAlreadyExists = [[NSFileManager defaultManager] fileExistsAtPath:databasePath];

// Open the database and store the handle as a data member
if (sqlite3_open([databasePath UTF8String], &databaseHandle) == SQLITE_OK)
{

    // Create the database if it doesn't yet exists in the file system
    if (!databaseAlreadyExists)
    {
        // Get the path to the database in the application package
        NSString *databasePathFromApp = [[NSBundle mainBundle] pathForResource:@"wine" ofType:@"sqlite"];
        //NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"wine.sqlite"];

        // Copy the database from the package to the users filesystem
        [[NSFileManager defaultManager] copyItemAtPath:databasePathFromApp toPath:databasePath error:nil];

        NSLog(@"Database created");
    }
}

}

Answer 1

There is a logic error, you check for databaseAlreadyExists inside the

if (sqlite3_open([databasePath UTF8String], &databaseHandle) == SQLITE_OK) { ... }

block.

What you probably meant is

// Check to see if the database file already exists
bool databaseAlreadyExists = [[NSFileManager defaultManager] fileExistsAtPath:databasePath];

// Create the database if it doesn't yet exists in the file system
if (!databaseAlreadyExists)
{
    // Get the path to the database in the application package
    NSString *databasePathFromApp = [[NSBundle mainBundle] pathForResource:@"wine" ofType:@"sqlite"];

    // Copy the database from the package to the users filesystem
    [[NSFileManager defaultManager] copyItemAtPath:databasePathFromApp toPath:databasePath error:nil];

    NSLog(@"Database created");
}

// Open the database and store the handle as a data member
if (sqlite3_open([databasePath UTF8String], &databaseHandle) == SQLITE_OK)
{
   ...
}

Answer 2

you open a DB (making a new 0 byte one if it isnt there using sqlite3_open and THEN copy the shipped one right where the new DB should be..

• you check if DB_docs is there
• but then you open DB_docs with sqlite no matter what
• and THEN you try copy it from the bundle into the OPENED File path

---

-(void)initDatabase
{
    // Create a string containing the full path to the sqlite.db inside the documents folder
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *databasePath = [documentsDirectory stringByAppendingPathComponent:@"wine.sqlite"];

    // Check to see if the database file already exists
    BOOL databaseAlreadyExists = [[NSFileManager defaultManager] fileExistsAtPath:databasePath];

    // Create the database if it doesn't yet exists in the file system
    if (!databaseAlreadyExists)
    {
        // Get the path to the database in the application package
        NSString *databasePathFromApp = [[NSBundle mainBundle] pathForResource:@"wine" ofType:@"sqlite"];

        // Copy the database from the package to the users filesystem
        [[NSFileManager defaultManager] copyItemAtPath:databasePathFromApp toPath:databasePath error:nil];

        NSLog(@"Database created");
    }

    // Open the database and store the handle as a data member
    if (sqlite3_open([databasePath UTF8String], &databaseHandle) == SQLITE_OK)
    {
        NSLog(@"db opened");
    }
}

Answer 3

I just use the following method written in AppDelegate, (It seems like the method body is huge, but it's actually not. Just remove all the comments and see for the clarity after you read the comments):

#pragma mark - SQLite DB
// SQLite Copy the Database.
-( void ) checkAndCreateDatabase
{
// Check if the SQL database has already been saved to the users phone, if not then copy it over
BOOL success;

NSString *databasePath = [LIBRARY_DIR_PATH stringByAppendingPathComponent:DATABASE_NAME];
NSLog(@"%@",databasePath);

// Create a FileManager object, we will use this to check the status
// of the database and to copy it over if required
NSFileManager *fileManager = [NSFileManager defaultManager];

// Check if the database has already been created in the users filesystem
success = [fileManager fileExistsAtPath:databasePath];
// If the database already exists then return without doing anything
if(success) return;

NSLog(@"DB WASN'T THERE! SO GONNA COPY IT!");

// If not then proceed to copy the database from the application to the users filesystem
// Get the path to the database in the application package
NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:DATABASE_NAME];
success = [fileManager fileExistsAtPath:databasePathFromApp];
if (success) {
    NSLog(@"SIMULATOR FOUND DB FROM APP, GONNA COPY IT");
} else {
    NSLog(@"SIMULATOR COULDN'T FIND DB\nIT SHOULD BE IN : %@\nPlease check if you have added the DB file and selected its target", databasePathFromApp);
}

// Copy the database from the package to the users filesystem
[fileManager copyItemAtPath:databasePathFromApp toPath:databasePath error:nil];

}

And call that method within

 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 

As follows:

//Copy the SQLite3 DB File
[self checkAndCreateDatabase];

Hint: Keep in mind that you need to add the SQLite DB file to your correct target membership when you drag and drop the db file to the XCode Project.