Core Data in IOS (for Beginners)

Core Data in IOS (for Beginners)

Introduction
Core Data is a schema-driven object graph management and persistence framework. 
Fundamentally, Core Data helps you to save model objects (in the sense of the model-view-controller design pattern) to a file and get them back again.

Core Data is available on iOS 3.0 and later.

Reference : - http://developer.apple.com/library/ios/#documentation/DataManagement/Conceptual/iPhoneCoreData01/Introduction/Introduction.html 

--------------------------------------------------------------------------------------

What i am going to do is...

Step 1

Create a ARC Project ....

Click the ARC also

Step 2

Click the "CoreDataTute.xdatamodeled"

Click Add Entity icon and type Student(Table name)

 Click the plus Sign to add Attribute

Step 3

click this icon to see the table

Step 4

Add new class for your Project

Step 5

Type this code in your  .h class (which you add new class in above)

#import <UIKit/UIKit.h>

@interface InsertDataViewController : UIViewController

{

 IBOutlet UITextField *nameField;

}

-(IBAction)save;

-(IBAction)Fetch;

@end

----------------------------------------------------------------

Step 6

Type this code in your  .m class (which you add new class in above)

Import the "AppDelegate.h"  .m class to your class

-----------------------------------------------------------------------------------------------------------------------

#import "InsertDataViewController.h"

#import "AppDelegate.h"

@interface InsertDataViewController ()

@end

@implementation InsertDataViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

{

self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

if (self) {

// Custom initialization

}

return self;

}

- (void)viewDidLoad

{

[super viewDidLoad];

// Do any additional setup after loading the view from its nib.

}

-(IBAction)save{

AppDelegate *appDelegate=(AppDelegate *)[[UIApplication sharedApplication]delegate];

//Entity for table name : Team

NSEntityDescription *entity=[NSEntityDescription insertNewObjectForEntityForName:@"Student" inManagedObjectContext:appDelegate.managedObjectContext];

//set value for the column name

[entity setValue:nameField.text forKey:@"name"];

NSError *error;

//its returns true when values inserted in database succesfuly otherwise false

BOOL isSaved= [appDelegate.managedObjectContext save:&error]; 

NSLog(@"Successfully Saved : flags @%d",isSaved);

}

-(IBAction)Fetch{

AppDelegate *appDelegate=(AppDelegate *)[[UIApplication sharedApplication]delegate];

//create Entity object for Table : Student

NSEntityDescription *entity=[NSEntityDescription entityForName:@"Student" inManagedObjectContext:appDelegate.managedObjectContext];

//create fetch request

NSFetchRequest *fetchRqst=[[NSFetchRequest alloc]init];

[fetchRqst setEntity:entity];

//Get all rows in mutable array

NSMutableArray *array=[[appDelegate.managedObjectContext executeFetchRequest:fetchRqst error:nil]mutableCopy];

//Core data return each row as managed object so we can access rows values through key value pair

for(NSManagedObject *obj in array)

{

   NSLog(@"SLIIT Student Names: %@\n",[obj valueForKey:@"name"]);

}

}

- (void)didReceiveMemoryWarning

{

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end

-----------------------------------------------------------------------------------

Step 7

Design the following Ui and Connect those Method like this.....

Step 8

 go to the AppDelegate.m class and set Above viewController(in my case it is  InsertDataViewController)  as a Root View Controller

 to do that import view controller Header file to the AppDelegate.h class 

and change the code of   

"- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions"  method in AppDelegate.h

#import "InsertDataViewController.h"

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

{

self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];

// Override point for customization after application launch.

InsertDataViewController *rootViewController=

[[InsertDataViewController alloc] initWithNibName:@"InsertDataViewController" bundle:nil];

[self.window setRootViewController:rootViewController];

self.window.backgroundColor = [UIColor whiteColor];

[self.window makeKeyAndVisible];

return YES;

}

--------------------------------------------------------------------------------------------------------------

Step 9

Run Your App & insert some data and Click the fetch button ....

• After click Save Button

this mean your successfully  added .................!

• After Click Fetch Button

Good Luck!

Tutorial List

1. SQLite Based iPhone Application
2. json with IOS (Basic) - Tutorial
3. Simple Table View in IOS
4. Load Distinct Images from array into UITableView
5. Simple UIPickerView Example
6. Tab Bar Application Part 1
7. Tab Bar Application Part 2
8. Tab Bar Application Part 3 ( with Login Screen )
9. Tab Bar Application Part 4 ( Navigation )
10. Table View Design in IOS Part 1
11. Table View Design in IOS Part 2 ( Time Table )
12. How to Add search bar in Table View
13. Local Notification in IOS
14. Core Data (For Beginners )
15. Core Data Tute 2 (Add/Delete/Search)
16. Core Data Tute 3 (Two table)
17. Custom Cell in UITableview
18. Lazy Loading
19. Pull to Refresh in TableView
20. Working with keyboard in Objective C - Part 1