what does means core data migration?

Question

What Does means Core Data Migration and why we used this?

Sachin Bhardwaj · Answer

core data is a framework but it work just like data base in this we make entity and it's attribute to save data. Core data migration In the end we've worked around this situation by putting the user's data into a plist file (there's a fairly limited amount of this) and retaining the Core Data database to use solely for reference data in the system so it can be overwritten in future without worry. A lightweight migration updates the data model on first run and then a one off migration call creates and populates the user data plist file renames the v1 core data persistent store *_migrated.sqlite copies the v2 sqlite database from the bundle into the documents dir then resets the MOM and sets the MOM MOC and Persistent Store to nil so that the next time Core Data starts it uses the v2 sqlite database as its Persistent Store. Phew. I hope this makes some sense to anyone reading it feel free to ask for any other details but it was honestly a lot simpler than it all sounds!