Question

I am using sqlite3 for my iOS project.
When login/logout i want to recreate the whole db.
(i can do “delete from table;” but there are ~10 tables and when i need a table more i have to be careful about writing the delete code too)
So i searched for deleting the db; but i found that it can not be done with query.
It is said that i have to remove it from filesystem;
my code is;

AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
NSString *dbPathDB=[appDelegate getDBPath];//dbname.sqlite
//to remove the db
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath =  [documentsDirectory stringByAppendingPathComponent:@"dbname.sqlite"];

//both of them works same if([[NSFileManager defaultManager] fileExistsAtPath:filePath]){
if(filePath){
    NSLog(@"it is removed now");
    [[NSFileManager defaultManager] removeItemAtPath:filePath error:nil];
}

//recreating the db
if (sqlite3_open([dbPathDB UTF8String], &database) == SQLITE_OK) {
    NSLog(@"db is created");

}

When i try it on device, when i first login (no removing database yet) everything is ok, when i logout and login again, i got errors about inserting the data (but it can connect to db, that part works, error is about inserting the same row again).

And i stop the device and run it again and login i got no insert errors because the db is clean..
It looks like db file is removed but db is on cache or sth like that? How can i remove and create the same db and then insert the data without errors?

Answer 1

This one works:

-(void)removeDB {
    // Check if the SQL database has already been saved to the users phone
    // if not then copy it over
    BOOL success;
    NSError *error;
    NSFileManager *fileManager = [NSFileManager defaultManager];
    AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
    success = [fileManager fileExistsAtPath:[appDelegate getDBPath]];
    if(success) {
        [fileManager removeItemAtPath:[appDelegate getDBPath] error:&error];
        NSLog(@"This one is the error %@",error);
        return;
    }
    //recreating the db
    if (sqlite3_open([[appDelegate getDBPath] UTF8String], &database) == SQLITE_OK) {
        NSLog(@"db is created");
    }
}