How to restrict entry of null value in coredata?
问题 I am working on XMLparsing based project and I used coredata to store url . But some time coredata enter's null value I don't know why such type of problem occurs. Here is my code which I have tried. - (void)feedParserDidFinish:(MWFeedParser *)parser { NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"demo"]; fetchRequest.predicate = [NSPredicate predicateWithFormat:@"urloffeed = %@", self.Feedlink]; NSManagedObjectContext *context = [self managedObjectContext]; if (