coredata - fetch one attribute into an array

Question

Aim: I would like to fetch the value of one attribute (from an entity) from the database (core data) into an array.

Example

Answer 1

You can avoid the last for loop,

Instead of,

NSMutableArray *employeeIDs = [NSMutableArray array];

for(id currentRecord in results)
{
    [employeeIDs addObject:[currentRecord objectForKey:@"employeeID"]];
}

Try this,

NSMutableArray *employeeIDs = [results valueForKey:@"employeeID"];

Answer 2

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"];