parse-platform - 在 Parse.com 中使用指针用户查询

Question

我在我的应用程序中使用 Parse.com，我创建了一个“帖子”类，在里面我有一个指针，它指定哪个用户发送了帖子。现在我在帖子的时间线上看到了创建帖子的用户名的时间。由于用户是指针，我无法正确查询，您知道我该如何解决这个问题吗？

Answer 1

诀窍是使用 PFQuery includeKey 让 Parse 自动填充相关的指针数据。user 数据将被下载，无需您再次查询。

PFQuery *query = [PFQuery queryWithClassName:@"Post"];

// Include the user data with each post
[query includeKey:@"title_of_userpointer_column"];

[query findObjectsInBackgroundWithBlock:^(NSArray *postObjects, NSError *error)
 {
     if (!error) {
         NSLog(@"Successfully retrieved: %d items", [postObjects count]);

         // postObjects now contains the latest 100 Posts, and the "title_of_userpointer_column" field
         // has been populated.
         // For example:
         for (PFObject * postObject in postObjects) {

             // This does not require a network access.
             PFObject *postAuthor = [postObject objectForKey:@"title_of_userpointer_column"];
             NSLog(@"retrieved related Post Author: %@", postAuthor);
         }
 }