如何在 Backendless.com 中增加字段

Question

下面是我拥有的表结构的概述

    Table data
----------------------------------
-             User               -
----------------------------------
| objectId |   name   | password |
----------------------------------
| z12ttttt | Matt     | hidden   |
| z12zzzzz | Jobs     | hidden   |
| z12bbbbb | Ballu    | hidden   |
| z12aaaaa | Stephin  | hidden   |
----------------------------------

--------------------------------------------------
-                       Post                     -
--------------------------------------------------
| objectId |   post    |  postBy  | likesCounter |
--------------------------------------------------
| blabla   | Head Pain | z12ttttt |      0       |
| blab12   | Back Pain | z12ttttt |      0       |
| blab23   | Sleepy    | z12ttttt |      0       |
| blab90   | Head Pain | z12zzzzz |      0       |
| blab90   | lets Dance| z12bbbbb |      0       |
| blab90   | lets jump | z12aaaaa |      0       |
--------------------------------------------------
//postBy has a 1 to 1 relationship with User table

目标：所有用户都可以查看彼此的帖子。现在，当用户喜欢某人的帖子时，该帖子的 likeCounter 应该增加 1。

问题：我找不到更新likeCounter 的持久方法。唯一可行的方法是

1) 检索帖子

2) 做likeCount++

3) 保存帖子

如您所见，存在数据持久性问题。如果你能告诉我一个可行的代码，请帮助它会更好。虽然我找到了This like，但我不知道如何实现它

Answer 1

看看 Backendless Atomic Counters API。

这是伪代码：

    //Create counter for every user by it`s objectId.
    var objectId = Post.getObjectId();
    // get counter manager
    var counter = Backendless.Counters.of( counterName );
    // increment or decrement
    counter.incrementAndGet( async );

文档中描述了所有场景：https://backendless.com/documentation/utilities/js/ut_atomic_counters_api_js.htm。