iPhone CoreData join
- by Ken
Hi guys, long time reader, first time poster.
(A link to this schema is located here)
http://www.weeshsoft.com/pix/DatabasePic.jpg
I'm trying to get all LanguageEntries from a database for a given category.categoryName and languageset.languageSetName e.g.
NSFetchRequest* fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"LanguageEntry" inManagedObjectContext:del.managedObjectContext];
[fetchRequest setEntity:entity];
NSString* predicateString = [NSString stringWithFormat:@"Category.categoryName = %@ AND LanguageSet.languageSetName = %@",
@"Food", @"English####Spanish"];
fetchRequest.predicate = [NSPredicate predicateWithFormat:predicateString];
NSError *error = nil;
NSArray* objects = [del.managedObjectContext executeFetchRequest:fetchRequest error:&error];
This always returns 0 objects. If I set the predicate string to match on one relationship (e.g. Category.categoryName = Food or languageSet.languageSetName = English####Spanish) it will return data.
This is baffling, can anyone shed some light?
-Ken
