Question

我有两个子类PFObjects如下：

@interface BQQuestion : PFObject<PFSubclassing>

@property (retain) NSString *user;
@property (retain) NSString *questionText;
@property (retain) NSArray *answers; //this is intended to hold an array of BQAnswers 

+ (NSString *)parseClassName;

@end


@interface BQAnswer : PFObject<PFSubclassing>

@property (retain) NSString *user;
@property (retain) BQQuestion *question;
@property (retain) NSString *answerText;
@property int votes;

+(NSString *)parseClassName;

@end

我正在尝试使用以下代码将BQAnswers添加到BQQuestion的answers属性中：

    BQQuestion *t = [BQQuestion object];
    t.questionText = @"Another test";
    BQAnswer *one = [BQAnswer object];
    one.answerText = @"Very nice.";
    BQAnswer *two = [BQAnswer object];
    two.answerText = @"Good.";

    t.answers = @[one, two];

    [t saveInBackground];

t，一个和两个都保存到Parse云中，但是没有为BQQuestion.answers生成列，因此关联不会保存。我在这里弄错了什么？

任何帮助将不胜感激。谢谢！

Answer 1

指向PFObject数组的指针是PFRelation。为此，您将在Question对象中创建一个包含指向Answer对象的关系的列。我假设您的解析班被称为＆＃34;问题＆＃34;并且包含指向答案的关系的添加列称为＆＃34;答案＆＃34;

BQQuestion *question = [PFObject objectWithClassName:@"Question"];
PFRelation *answers = [t relationForKey:@"answers"];
for (PFObject *answer in answers) {
  [question add:answer];
}
[question saveInBackground];

要检索答案对象：

BQQuestion *question = //assume you have the question object;
PFRelation *answers = [question relationForKey:@"answers"];
PFQuery *query = [answers query];
[query findObjectsInBackgroundWithBlock:^(NSArray *results, NSError *error) {
    // results contains all the answers to that question
}];

将NSArray属性添加到子类PFObject

1 个答案: