how to fetch & store any column from coredata to array
- by user440485
Hi All,
I am working on page(Lesson) has button called "AddToFavorite".
when i click on this button lessonID,lessonHeading is added in the Coredata.
- (NSFetchedResultsController *)fetchedResultsController {
// Set up the fetched results controller if needed.
if (fetchedResultsController != nil) {
return fetchedResultsController;
}
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Favorites" inManagedObjectContext:managedObjectContext];
[fetchRequest setEntity:entity];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"lessonHeading" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:@"lessonHeading" cacheName:@"Root"];
self.fetchedResultsController = aFetchedResultsController;
self.fetchedResultsController.delegate = self;
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptor release];
[sortDescriptors release];
return fetchedResultsController;
}
-(void)addToFavorites
{
UIAlertView *alert=[[UIAlertView alloc]initWithTitle:nil message:@"Lesson has been added successfully to your Favorite List" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
[alert release];
//Create a new managed object context for the new book -- set its persistent store coordinator to the same as that from the fetched results controller's context.
NSManagedObjectContext *addingContext = [[NSManagedObjectContext alloc] init];
self.addingManagedObjectContext = addingContext;
[addingManagedObjectContext setPersistentStoreCoordinator:[[fetchedResultsController managedObjectContext] persistentStoreCoordinator]];
Favorites *fav = [NSEntityDescription insertNewObjectForEntityForName:@"Favorites" inManagedObjectContext:addingContext];
fav.lessonID=[[data objectAtIndex:count]objectForKey:@"LessonID"];
fav.lessonTitle=[[data objectAtIndex:count]objectForKey:@"LessonTitle"];
[self didFinishWithSave:YES];
[addingContext release];
}
My problem is that i want to show an alert if this lessonID is already existing in the
coreData.
show guide me how i can match the current page lessonID with the existing lessonID's in the CoreData.
I am using CoreData 1st time.so sory for any mistake ...& thanks for ypur help frnds.
