ios - error while fetching image from photo library and save to coredata -

error below:

terminating app due uncaught exception 'nsinternalinconsistencyexception', reason: '+entityforname: not locate entity named 'contacts' in model.'

code of fetching data photo library:

- (void)imagepickercontroller:(uiimagepickercontroller *)picker didfinishpickingmediawithinfo:(nsdictionary *)info  {          [picker dismissmodalviewcontrolleranimated:yes];       uiimage *img = [info objectforkey:@"uiimagepickercontrolleroriginalimage"];       nserror *error;       nsmanagedobjectcontext *context;       context = [self managedobjectcontext];       nsmanagedobject *object =  [nsentitydescription insertnewobjectforentityforname:@"contacts" inmanagedobjectcontext:context];       nsdata *data=uiimagejpegrepresentation(img,0.0);      [object setvalue:data forkey:@"image"];      [context save:nil];      [self fetchdata];   } 

my fetch() method coding.

-(void)fetchdata{  nsmanagedobjectcontext *context = [self managedobjectcontext]; nsfetchrequest * request = [[nsfetchrequest alloc] init]; [request setentity:[nsentitydescription entityforname:@"contacts"                                inmanagedobjectcontext:context]]; nserror * error = nil; nsarray * objects = [context executefetchrequest:request error:&error]; if ([objects count] > 0) {     nsmanagedobject *object = objects[0];             data1 = [object valueforkey:@"image"];     image2 = [[uiimage alloc]initwithdata:data1];     imgviewofprofilepic.image=image2;  }} 

and coding of nsmanagedobjectcontext()

- (nsmanagedobjectcontext *)managedobjectcontext { nsmanagedobjectcontext *context; id delegate = [[uiapplication sharedapplication] delegate]; if ([delegate performselector:@selector(managedobjectcontext)]) {     context = [delegate managedobjectcontext];     }   return context;  }