iPhone - sorting the results of a core data entity
- by Digital Robot
I have a core data entity that represents the attributes of a product, as number, price, etc. The product number is a NSString property and follows the form
X.y
where X is a number variable of digits and Y is one digit. For example. 132.2, 99.4, etc.
I am querying the database to obtain the list of product numbers in order:
The code is like this:
+ (NSArray*)todosOsItens:(NSString *)pName inManagedObjectContext:(NSManagedObjectContext *)context
{
Product *aProduct = [Product productWithName:pName inManagedObjectContext:context];
NSArray *all = nil;
NSFetchRequest *request = [[NSFetchRequest alloc] init];
request.entity = [NSEntityDescription entityForName:@"Attributes" inManagedObjectContext:context];
request.predicate = [NSPredicate predicateWithFormat:
@"(belongsTo == %@)", aProduct];
[request setResultType:NSDictionaryResultType];
[request setReturnsDistinctResults:YES];
[request setPropertiesToFetch:[NSArray arrayWithObject:item]];
NSSortDescriptor *sortByItem = [NSSortDescriptor sortDescriptorWithKey:@"ProductNumber" ascending:YES];
NSArray *sortDescriptors = [NSArray arrayWithObject:sortByItem];
[request setSortDescriptors:sortDescriptors];
NSError *error = nil;
all = [[context executeFetchRequest:request error:&error] mutableCopy];
[request release];
return all;
}
but this query is not returning the sorted results. The results are coming on their natural order on the database.
How do I do that?
thanks.
