objective c - iOS - Core data : Fetch and delete , one row at a time -

i have objects stored in core data. want fetch objects 1 row @ time , after finish operation on it, want delete row/object core data. , again fetch next row , delete row, , on until core data empty. (with approach) code store objects in core data :

-(bool)saveproduct:(addproduct *)addproduct withimagensdata:(nsdata *)imagensdata error:(nserror *)error{     nsmanagedobject *object = [nsentitydescription insertnewobjectforentityforname:@"device" inmanagedobjectcontext:self.managedobjectcontext];     device *device = (device *)object;     [device setvalue:addproduct.currencytype forkey:@"currencytype"];     [device setvalue:[nsnumber numberwithdouble:addproduct.latitude] forkey:@"latitude"];     [device setvalue:[nsnumber numberwithdouble:addproduct.longitude] forkey:@"longitude"];     [device setvalue:[nsnumber numberwithdouble:addproduct.price] forkey:@"price"];     return [self.managedobjectcontext save:&error]; } 

this fetch of devices , iterate through them, deleting objects after you've performed work on them:

nsmanagedobjectcontext *context = self.managedobjectcontext; nsfetchrequest *fetchrequest = [nsfetchrequest fetchrequestwithentityname:@"device"];  //fetch of devices nserror *error; nsarray *alldevices = [context executefetchrequest:fetchrequest error:&error]; if (error) {     nslog(@"error fetching devices! %@", error);     return; }  (device *device in alldevices) {     // perform operation on device      [context deleteobject:device]; } [context save:null];