CODEWITHSUNDEEP
iphoneobjective-cipadcore-data
PeterK
PeterK

Reputation: 4301

Updating app that includes pre-populated database

I have an application that is using a quite large database with approximately 3.000 records. Previously i have loaded the database when starting up the app for the first time but with the number of records i have now i am implementing a pre-populated database to save time.

My question is what is happening when updating the app, from appstore, to the device will the app know that there is an updated version of the database and load the new database or continue to use the database that is already active with the app?

I am using this code in my app to use the pre-populated Core Data DB:

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
  if (persistentStoreCoordinator != nil) {
    return persistentStoreCoordinator;
}

NSString *storePath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"database.sqlite"];

/*
 Set up the store.
 For the sake of illustration, provide a pre-populated default store.
 */
NSFileManager *fileManager = [NSFileManager defaultManager];
// If the expected store doesn't exist, copy the default store.
if (![fileManager fileExistsAtPath:storePath]) {
    NSString *defaultStorePath = [[NSBundle mainBundle] pathForResource:@"database" ofType:@"sqlite"];
    if (defaultStorePath) {
        [fileManager copyItemAtPath:defaultStorePath toPath:storePath error:NULL];
    }
}

NSURL *storeUrl = [NSURL fileURLWithPath:storePath];

NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil]; 
persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: [self managedObjectModel]];

NSError *error;
if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:options error:&error]) {
    // Update to handle the error appropriately.
    NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
    exit(-1);  // Fail
}    

return persistentStoreCoordinator;

}

Upvotes: 0

Views: 336

Answers (2)

sergio
sergio

Reputation: 69027

Let's say that you app currently in the app store is version 1.0. This app downloaded a DB on its first launch. Now, you are going to publish a new version 1.1, which will bundle the DB within the app itself.

When a user of the existing app (1.0) will upgrade to 1.1, what happens is fully under your control. Indeed, version 1.1 could check, on its first launch, for the existence of the DB in the user directory where version 1.0 installed it. In case, it is there, then version 1.1 knows it should upgrade the DB by copying it over from the resource directory.

Actually, the DB must be copied over to the user directory in any case, so by checking the you could make sure that no user data will be wiped out.

In general, you might store a version number in NSUserDefaults, so that each future version of your app has a way to know whether it is an upgrade os a new install (if the version number is there, then it is an upgrade from that specific version, otherwise it is a new install).

Upvotes: 2

Omar Abdelhafith
Omar Abdelhafith

Reputation: 21221

When you update the app, the files already created will still be there, so older versions of your app will still use the old database that you created in your old version

Upvotes: 0

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