CoreDataの基本使用
2994 ワード
NSEntityDescription:エンティティオブジェクトの取得NSFetchRequest:リクエストボディNSPredicate:リクエスト条件NSSortDescriptor:ソート
, UIApplication
@property(nonatomic,strong)AppDelegate *App;
self.App = [UIApplication sharedApplication].delegate;
1. ( )
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Person" inManagedObjectContext:self.App.managedObjectContext];
2. CoreData initWithEntity
Person *person = [[Person alloc] initWithEntity:entity insertIntoManagedObjectContext:self.App.managedObjectContext];
3. person
Person.name = @" ";
Person.age = 18;
4.
[self.App saveContext];
1. ( )
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Person" inManagedObjectContext:self.App.managedObjectContext];
2.
NSFetchRequest *requset = [[NSFetchRequest alloc] init];
3.
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"age = 18"];
4. entity , predicate
requset.entity = entity;
requset.predicate = predicate;
5.
NSArray *array = [self.managedObjectContext executeFetchRequest:requset error:nil];
6. , deleteObject:
for (Student *stu in array) {
[self.managedObjectContext deleteObject:stu];
}
7.
[self.App saveContext];
1.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Person" inManagedObjectContext:self.App.managedObjectContext];
2.
NSFetchRequest *requset = [[NSFetchRequest alloc] init];
3.
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"age = 18"];
4. entity , predicate
requset.entity = entity;
requset.predicate = predicate;
5.
NSArray *array = [self.managedObjectContext executeFetchRequest:requset error:nil];
6. ,
for (Student *stu in array) {
stu.name = @" ";
}
7.
[self.App saveContext];
1. ( )
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Person" inManagedObjectContext:self.App.managedObjectContext];
2.
NSFetchRequest *requset = [[NSFetchRequest alloc] init];
3.
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"age = 18"];
4. entity , predicate
requset.entity = entity;
requset.predicate = predicate;
5.
NSArray *array = [self.managedObjectContext executeFetchRequest:requset error:nil];