CoreData

데이타베이스	코어데이타
데이타베이스 자체	관리객체 컨텍스트(Managed Object Context)	관리객체를 담는 그릇
테이블 구조(스키마)	엔티티 (NSEntityDescription)
테이블 구조를 이루는 세부컬럼 정보	프로퍼티 (Property)
테이블 내의 하나의 레코드	관리객체 (Managed Object)
SQL문 (예: select * from)	갬색 요청(Fetch Request)
SQL 조건문 (where age > 20)	조건 서술(Predicate)
저장소 관리자	저장소 관리자 (Persistent Store Coordinator)	컨텍스트 내용을 파일이나 DB에 저장하는 객체

//프로그램종료시 저장

-(void)applicationWillTerminate:(NSNotification *)notification{

coreDataAppDelegate *appDelegate = [UIApplication sharedApplication] delegate];

NSManagedObjectContext *context = [appDelegate managedObjectContext];

NSError *error;

for(int i=1;i<=3;i++)

{

NSString *fieldName = [NSString stringWithFormat:@"line%d",i];

UITextField *field = [self valueForKey:fieldName];

NSFetchRequest *request = [NSFetchRequest alloc] init];

NSEntityDescription *entity = [NSEntityDescription entityForName:@"Line" inManagedObjectContext:context];

[request setEntity:entity];

NSPredicate *pred = [NSPredicate predicateWithFormat:@"(lineNum = %d)", i];

[request setPredicate:pred];

NSManagedObject *theLine = nil;

NSArray *array = [context executeFetchRequest:request error:&error];

if([array count] > 0)

theLine = [array objectAtIndex:0];

else

theLine = [NSEntityDescription insertNewObjectForEntityForName:@"Line"                    inManagedObjectContext:context];

[theLine setValue:[NSNumber numberWithInt:i] forKey:@"lineNum"];

[theLine setValue:field.text forKey:@"lineText"];

[request release];

}

[context save:&error];

}

-(void)ViewDidLoad{

coreDataAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];

NSManagedObjectContext *context = [appDelegate managedObjectContext];

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

NSEntityDescription *entity = [NSEntityDescription entityForName:@"Line" inManagedObjectContext:context];

[request setEntioty:entity];

NSError *error;

NSArray *array = [context executeFetchRequest:request error:&error];

for(ManagedObject *oneObject in array)

{

NSNumber *lineNum = [oneObject valueForKey:@"lineNum"];

NSString *lineText = [oneObject valueForKey:@"lineText"];

NSString *field  = [NSString stringWithFormat:@"line%d", lineNum];

UITextField *txtField = [self valueForKey:field];

txtField.text = lineText;

}

[request release];

UIApplication *app = [UIApplication sharedApplication];

[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationWillTerminate:) name:UIApplicationWillTerminateNotification object:app];

}