This is the gist of using CoreData in iOS

programming--ios-coredata

FailedBankInfo.h
-----------------
#import <CoreData/CoreData.h>

@class FailedBankDetails;

@interface FailedBankInfo : NSManagedObject

@property (nonatomic, retain) NSString * name;
@property (nonatomic, retain) NSString * city;
@property (nonatomic, retain) NSString * state;
@property (nonatomic, retain) FailedBankDetails *details;

@end

FailedBankInfo.m
-----------------

@implementation FailedBankInfo

@dynamic name;
@dynamic city;
@dynamic state;
@dynamic details;

@end



    
Inserting and retrieving the data
----------------------------------

NSManagedObjectContext *context = [self managedObjectContext];
FailedBankInfo *failedBankInfo = [NSEntityDescription
                                  insertNewObjectForEntityForName:@"FailedBankInfo"
                                  inManagedObjectContext:context];
failedBankInfo.name = @"Test Bank";
failedBankInfo.city = @"Testville";
failedBankInfo.state = @"Testland";
FailedBankDetails *failedBankDetails = [NSEntityDescription
                                        insertNewObjectForEntityForName:@"FailedBankDetails"
                                        inManagedObjectContext:context];
failedBankDetails.closeDate = [NSDate date];
failedBankDetails.updateDate = [NSDate date];
failedBankDetails.zip = [NSNumber numberWithInt:12345];
failedBankDetails.info = failedBankInfo;
failedBankInfo.details = failedBankDetails;
NSError *error;
if (![context save:&error]) {
    NSLog(@"Whoops, couldn't save: %@", [error localizedDescription]);
}

// Test listing all FailedBankInfos from the store
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"FailedBankInfo"
                                          inManagedObjectContext:context];
[fetchRequest setEntity:entity];
NSArray *fetchedObjects = [context executeFetchRequest:fetchRequest error:&error];
for (FailedBankInfo *info in fetchedObjects) {
    NSLog(@"Name: %@", info.name);
    FailedBankDetails *details = info.details;
    NSLog(@"Zip: %@", details.zip);
}