Question

Hi I am fairly new to core data and have recently started doing some tutorials. I have successfully added new data via core data but am struggling to overwrite the data. I have a textfield where I want to be able to save the text written in that textfield to core data. This is how I have added new data. Can anyone lead me in the right direction?

Thank you

P.S. I believe it has to do with the way I do “insertNewObjectForEntityForName”

-(IBAction)saveData
{

AppDelegate *appDelegate = 
[[UIApplication sharedApplication] delegate];

NSManagedObjectContext *context = 
[appDelegate managedObjectContext];
NSManagedObject *newContact;
newContact = [NSEntityDescription
              insertNewObjectForEntityForName:@"Gameinfo"
              inManagedObjectContext:context];
[newContact setValue:[self valuefromtextfield] forKey:@"score"];
//[newContact setValue:@"mark" forKey:@"currentLevel"];
NSError *error;
[context save:&error];

 }

Answer 1

When you use insertNewObjectForEntityForName you are creating a NEW entity. If you want to edit an existing entity you need to

AppDelegate *app = [[UIApplication sharedApplication] delegate]
NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:@"Gameinfo"];
NSError *error = nil;
NSArray *someArray = [app.managedObjectContext executeFetchRequest:request error:&error];

Then someArray has all of the entities named Gameinfo in it. Find the one you want and edit whatever properties you want. Then call save on the managed object context.