Presentation delivered by me in weekly team tech sessions on iOS and Android.

1. Lightweight Migration
iOS
Hussain Mansoor

2. Migration
ORM (CoreData) feature
Automatically moves data from previous version
to new version from table/entities or column/keys
Lightweight migration
Custom Migration
Required mapping model

3. Steps to create Model file
Select Model File
Editor -> Add Model Version
Select 2nd Model file change what you want*
Select Base Model File
Select Utilities Tab
File Inspector tab
Change Model version -> current

4. Enable Migration
In Magical Records
[MagicalRecord
setupCoreDataStackWithAutoMigratingSqlite
StoreNamed:@”ModelFileName"];

5. Enable Migration
In Manual Core Data handling
NSDictionary *options = [NSDictionary
dictionaryWithObjectsAndKeys: [NSNumber
numberWithBool:YES],
NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES],
NSInferMappingModelAutomaticallyOption, nil];
Use this “options“ Dictionary in creating persistent store co-
ordinator
[_persistentStoreCoordinator
addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil URL:storeURL options:options
error:&error];

6. References/Reading
https://developer.apple.com/library/mac/documen
tation/Cocoa/Conceptual/CoreDataVersioning/Art
icles/vmLightweightMigration.html#//apple_ref/do
c/uid/TP40004399-CH4-SW1
http://www.raywenderlich.com/86136/lightweight-
migrations-core-data-tutorial
http://www.raywenderlich.com/27657/how-to-
perform-a-lightweight-core-data-migration