Aim: I would like to fetch the value of one attribute (from an entity) from the database (core data) into an array.
Example
One way of doing it is-
NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"Employees"];
fetchRequest.resultType = NSDictionaryResultType;
NSError *error = nil;
NSArray *results = [self.managedObjectContext executeFetchRequest:fetchRequest
error:&error];
NSMutableArray *employeeIDs = [results valueForKey:@"employeeID"];