objective-C IOS core data 使用NSPredicate查询

[zhanghanivy]

一个表里面有firstname ，lastname两个属性，我想查出firstname或者lastname中包含form的项
分别查我会，不知道怎么合并

NSString * searchTerm = [searchBar text];
[NSFetchedResultsController deleteCacheWithName:@"Master"];
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Contact" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];

// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
NSString *form = [NSString stringWithFormat:@"%@*",searchTerm ];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(firstname like %@)",form];
// NSLog(@"%@",searchBar.text);
[fetchRequest setPredicate:predicate];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"firstname" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];

[fetchRequest setSortDescriptors:sortDescriptors];

// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:@"Master"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;

[相奇]

我也不会。。。

也希望有详细的解答