将sqlite文件复制到Documents文件夹后，文件变空

Question

I have a problem with .db file that after copying into Documents directory getting 0 KB of size, while the original file is 137KB. I tried to open my copied file in SQLite Manager. It opens, doesn't complaint about file corruption... It just doesn't contain a single table.

My code to copy the file:

- (void) createEditableDatabase
{
    BOOL success; 
    NSFileManager *fileManager = [NSFileManager defaultManager]; 
    NSError *error;
    NSString *writableDB = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"yc_ch.db"];
    success = [fileManager fileExistsAtPath:writableDB];
    if (success)
    {
        return;
    }
    NSString *defaultPath = [[NSBundle mainBundle] pathForResource:@"yc_ch" ofType:@"db"];
    error = nil;
    success = [fileManager copyItemAtPath:defaultPath toPath:writableDB error:&error];
    if (!success) 
    {
        NSAssert1(0, @"Failed to create writable database file:%@", [error localizedDescription]);
    }
}

Checks if file exist, if not copies. The check happens in RootViewController's

- (void)viewDidLoad
{
    self.subCountriesArr=[[NSMutableArray alloc]initWithCapacity:1];
    NSMutableArray *subCountriesTemp=[[[NSMutableArray alloc]init]autorelease];

    DBAccess *dbAccess=[[DBAccess alloc]init];
    [dbAccess createEditableDatabase]; //method to copy file
    subCountriesTemp=[dbAccess getSubCountries];

    [dbAccess closeDataBase];
    [dbAccess release];
}

So, that's strange for me. Any help please? Thank you in advance.

Answer 1

After all , I did like this.It worked for me.

1) click on the .db file.

2)then find the fileInspector on right side,click the file inspector

3) check the target membership of .db file whether checkbox is checked or not.

4)if not check the checkbox

Hope It will work...

Answer 2

How about you try it with this:

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *writableDB = [documentsDirectory stringByAppendingPathComponent:@"yc_ch.db"];

NSFileManager *fileManager = [NSFileManager defaultManager];
if (![fileManager fileExistsAtPath:writableDB] ) {
    NSString *databaseFile = [[NSBundle mainBundle] pathForResource:@"yc_ch" ofType:@"db"];
    [fileManager copyItemAtPath:databaseFile toPath:writableDB error:nil];
    NSLog(@"database copied");
}

I don't think NSHomeDirectory is a valid way of accessing the documents directory....

Don't know for sure if this will solve it but it's worth a try.

Answer 3

I don't know if this helps but if you copy a core data '.sqlite' database it also copies it empty, but there are two more files '.sqlite-shm' and '.sqlite-wal'. If you copy those two more files with the same name of the destination with their respective extension the database is no longer empty.

Answer 4

Well, I've solved this problem. In my DBAccess class I had method:

-(void)initializeDataBase
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"yc_ch.db"];

   // NSString *path=[[NSBundle mainBundle] pathForResource:@"yc_ch" ofType:@"db"];
    if (sqlite3_open([path UTF8String], &database) == SQLITE_OK)
    {
        //
    }
    else
    {
        [self dbConnectionError];
    }
}

And it was called in init. -(void)initializeDataBase is fired at all. Now, this piece of code:

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:@"yc_ch.db"];

NSString *path=[[NSBundle mainBundle] pathForResource:@"yc_ch" ofType:@"db"];
if (sqlite3_open([path UTF8String], &database) == SQLITE_OK)

I call in every method separately. It helped.