ios - How do I delete a row from a Parse object? -

i have class on parse.com called "hospital", has few rows on it. want query rows in object, , selectively delete of them.

i figure need cycle through object, gathering objectids, , @ row associated each id figure out ones should deleted. can't find how anywhere. i've tried this:

pfquery *query = [pfquery querywithclassname:@"hospital"]; 

but returns object 0 objects inside it, when there row in parse.com database.

once part working, , objectids, seems can delete row following:

pfobject *testobject = [pfobject objectwithoutdatawithclassname:@"hospital" objectid:@"nmz8glj3re"];  [testobject deleteinbackgroundwithblock:^(bool succeeded, nserror *error) {  if (succeeded){  nslog(@"booooom"); // function refresh data  } else {  nslog(@"delete errir");  }  }]; 

pfquery *query = [pfquery querywithclassname:@"hospital"]; [query findobjectsinbackgroundwithblock:^(nsarray *hospitals, nserror *error) {     if (!error)     {         (pfobject *hospital in hospitals)         {             if ([hospital.objectid isequaltostring:@"nmz8glj3re"])             {                 [hospital deleteinbackgroundwithblock:^(bool succeeded, nserror *error) {                     if (succeeded){                         nslog(@"booooom"); // function refresh data                     } else {                         nslog(@"delete errir");                     }                 }];             }         }     }     else     {         nslog(@"%@",error);     }  }];