Firebase增加值而不读取先前的值? [英] Firebase increase value without reading previous value?

问题描述

我正在使用Firebase开发具有大量用户的ios应用程序.我需要根据用户的响应更新Firebase数据库中的特定字段值.有没有一种方法可以将特定字段的值增加一(1)，而无需读取其当前值.当多个用户试图同时增加同一字段的值时会发生什么?

I'm developing an ios application using Firebase it has huge users. I need to update particular field value in Firebase database based on user's response. Is there a way to increase particular field' value by one(1) without reading its current value. What will happen when several users trying to increase value of same field concurrently?

推荐答案

在客户端应用程序中，如果不读取值就无法增加值.如果有多个作者，则最后一个作者的值会覆盖其他所有内容.

From a client app, you cannot increment a value without reading it. If there are multiple writers, the last writer's value overwrites everything else.

如果要在有相同值的并发编写器时安全地增加值，请使用

If you want to safely increment a value when there are concurrent writers of the same value, use a transaction.

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