以一对多关系从 coredata 中获取所有对象

Posted 2023-03-04

【中文标题】以一对多关系从 coredata 中获取所有对象

【英文标题】：fetch all object from coredata in one-to-many relationship

【发布时间】：2012-05-26 11:19:13

【问题描述】：

这是我的Exercise 课程

@class Question;

@interface Exercise : NSManagedObject

@property (nonatomic, retain) NSNumber * aID;
@property (nonatomic, retain) NSString * name;
@property (nonatomic, retain) NSSet *listQuestion;
@end

@interface Exercise (CoreDataGeneratedAccessors)

- (void)addListQuestionObject:(Question *)value;
- (void)removeListQuestionObject:(Question *)value;
- (void)addListQuestion:(NSSet *)values;
- (void)removeListQuestion:(NSSet *)values;

@end 

这里是Question类

@class Exercise;

@interface Question : NSManagedObject

@property (nonatomic, retain) NSNumber * aID;
@property (nonatomic, retain) id jsAnswer;
@property (nonatomic, retain) Exercise *exercise;

@end

这些类是由 coredata 创建的 如何在每个练习中通过listQuestion 获取所有Question 对象

【参考方案1】：

这将为您提供给定练习的所有 Question 对象的数组：

NSArray *questions = [[exercise listQuestion] allObjects];