CoreData简单使用

NSManagedObject *managedObject = [NSEntityDescription insertNewObjectForEntityForName:@"Person" inManagedObjectContext:self.managedObjectContext];

NSString *name = @"JackChen";

// 通过KVC赋值

[managedObject setValue:name forKey:@"name"];

[managedObject setValue:@13 forKey:@"age"];

// 验证

NSError *error = NULL;

[managedObject validateValue:&name forKey:@"name" error:&error];

if (error) {

NSLog(@"%@",[error localizedDescription]);

}

// 添加数据

[self.managedObjectContext insertObject:managedObject];

Card *card = [NSEntityDescription insertNewObjectForEntityForName:NSStringFromClass([Card class]) inManagedObjectContext:self.managedObjectContext];

card.cardID = @"1345678";

[self.managedObjectContext insertObject:card];

// 保存

[self saveContext];

// 查询

NSFetchRequest *request = [[NSFetchRequest alloc] init];

// 去哪个对象查询

NSEntityDescription *entity = [NSEntityDescription entityForName:@"Person" inManagedObjectContext:self.managedObjectContext];

[request setEntity:entity];

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"name like 'Jack*'"];

[request setPredicate:predicate];

NSArray *arr = [self.managedObjectContext executeFetchRequest:request error:NULL];

for (NSManagedObject *obj in arr) {

NSLog(@"%@ --- %@",[obj valueForKey:@"name"], [obj valueForKey:@"age"]);

}