Dan Shelly questions

Dan Shelly answers

• Querying Core Data for Specific Attributes when Creating New Objects and returning the object if it exists, or creating a new one if it does not
• keypath objectID not found in entity exception
• NSFetchRequest for sub objects in rows
• NSFetchedResultsController - track changes only to a subset of the properties
• Chat, conversation, messaging - CoreData model
• How to force UNIDIRECTIONAL to-many relationship to persist
• Optimistic locking support in NSIncrementalStore subclass
• Core Data Model Design
• Core Data - break retain cycle of the parent context
• NSSortDescriptor - Sort descriptor based on another array