Core Data combined Query - iphone

Question

Hey, i have question related to CoreData. My iphone project has 2 Entities, Organisation and Brand with a 1 to many "BrandsToOrg" relationship and inverse.
So my project has a Mapview, where you can see all the Organisations and a little subview when you click on those Organisations.At the subview there is a "show Brands" Button, which should init a new TableView who only shows the brands belong to the seleceted organisation.
Any ideas how i can code that?
thx
NSPredicate *predicate = [NSPredicate predicateWithFormat: #"(TitleMedium == %#)",#"Rock Antenne"];????
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:self.entityName inManagedObjectContext:managedObjectContext];
[request setEntity:entity];
if(predicate != nil)
{
[request setPredicate:predicate];
}
// If a sort key was passed, use it for sorting.
NSString *sortKey=#"TitleMedium";
BOOL sortAscending=YES;
if(sortKey != nil)
{
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:sortKey ascending:sortAscending];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[request setSortDescriptors:sortDescriptors];
[sortDescriptors release];
[sortDescriptor release];
}
NSError *error;
NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy];
[request release];
[self setEntityArray:mutableFetchResults];

Answer 1

Here's an example of how you would do this with a top-level UITableView of orgs and a detailed table view of brands. At the top level, you do a fetch request for the orgs and display them. When a particular one is selected, you create the detail view of brands. The BrandsViewController object has a "org" property that tells is what to display; it can then refer to "org.brands" (which is the Core Data one-to-many relationship) to locate all the brands for that display. Note that you don't need to do an explicit Core Data fetch within the BrandsViewController to get the brands.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
BrandsViewController *targetViewController = [[BrandsViewController alloc]
initWithNibName:#"BrandsView" bundle:nil];
// pass managedObjectContext along to new view controller
targetViewController.managedObjectContext = self.managedObjectContext;
// Pass the selected org to the new view controller
targetViewController.org = (Organisation *)[fetchedResultsController objectAtIndexPath:indexPath];
[[self navigationController] pushViewController:targetViewController animated:YES];
[targetViewController release];
}