Firebase 查询多个 where 条件 [英] Firebase query for multiple where condition

问题描述

我需要

从 GameScores 中选择玩家姓名WHERE 部门 = 'HR' OR 部门 = 'IT' OR 部门 = '营销'

SELECT PlayerName FROM GameScores WHERE Department = 'HR' OR Department = 'IT' OR Department = 'Marketing'

在 Firebase for android 中，我不想要多次调用，只需要一次请求并获取与 where 子句键匹配的所有数据.我该怎么做?

In Firebase for android , I don't want multiple call, just one request and get all data that match with where clause key. How I can do it?

推荐答案

在 Firebase 中过滤多个值的属性的唯一方法是这些值是否在一个范围内.例如，您可以获得与您的值匹配的所有项目:

The only way to filter a property on multiple values in Firebase is if those values are in a range. For example, you could get all items matching your values with:

ref.child("GameScores")
   .orderByChild("Department")
   .startAt("HR")
   .endAt("Marketing")

这样做的问题是它还会匹配其他部门名称在HR 和Marketing 之间的分数，例如

The problem with this is that it also matches scores from other departments whose name is between HR and Marketing, such as

Firebase 实时数据库或 Cloud Firestore 无法将多个单独的值传递到查询中.您必须为每个值执行单独的查询并在客户端合并它们.

There is no way in either the Firebase Realtime Database or Cloud Firestore to pass multiple separate values into a query. You will have to execute a separate query for each value and merge them client-side.

另见:

• firebase 等价于 sql where in ()

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