问题描述
[newVehicle setValue: _txtFieldVehicleNumber.text forKey:@"number"]; [newVehicle setValue: lblFuelType.text forKey:@"fueltype"]; [newVehicle setValue: lblFuelUnit.text forKey:@"fuelunit"]; [newVehicle setValue: lblDistanceUnit.text forKey:@"distanceunit"];
我想更新名为Vehicle"的核心数据实体,对于该实体,我有几个属性,当我从实体中选择特定属性时,我想更新其中一些属性,但不是全部.那我该怎么办??
I want to update my core data entity named "Vehicle", for that entity I have several attributes and I want to update some of them but not all when I select particular attribute from the entity. So what should I do ??
推荐答案
您可以执行以下操作(近似代码.实现错误处理和检查语法).
you can do the following (approximate code. Implement error handling and check syntax).
NSFetchRequest *fetchRequest=[NSFetchRequest fetchRequestWithEntityName:@"Vehicle"]; NSPredicate *predicate=[NSPredicate predicateWithFormat:@"vehicle_id==%@",vehicle_id]; // If required to fetch specific vehicle fetchRequest.predicate=predicate; Vehicle *newVehicle=[[self.managedObjectContext executeFetchRequest:fetchRequest error:nil] lastObject]; [newVehicle setValue: _txtFieldVehicleNumber.text forKey:@"number"]; [newVehicle setValue: lblFuelType.text forKey:@"fueltype"]; [newVehicle setValue: lblFuelUnit.text forKey:@"fuelunit"]; [newVehicle setValue: lblDistanceUnit.text forKey:@"distanceunit"]; [self.managedObjectContext save:nil]