How to use entity with using managedObjectContext?

Question

I don't want to save to persistence storage. How can i use entity class without saving to persistence storage?

Answer 1

After creating the managed object context and the persistent core coordinator, you assign two persistent stores to the store coordinator:

NSPersistentStore *sqliteStore, *memoryStore;

sqliteStore = [coordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:nil error:&error];
if (sqliteStore == nil) {
    // ...
}
memoryStore = [coordinator addPersistentStoreWithType:NSInMemoryStoreType configuration:nil URL:nil options:nil error:&error];
if (memoryStore == nil) {
    // ...
}

Later, when you insert new objects to the context, you associate the new object either with the SQLite store or the in-memory store:

Records *record = [NSEntityDescription insertNewObjectForEntityForName:@"Records" inManagedObjectContext:context];
[context assignObject:poster toPersistentStore:memoryStore];
// or: [context assignObject:poster toPersistentStore:sqliteStore];
record.empID = ...;
record.name = ...;

Only the objects assigned to the SQLite store are saved to disk. Objects assigned to the in-memory store will be gone if you restart the application.