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

问题描述

我需要等价查询

从GameScores
中选择玩家名称WHERE Department ='HR'OR Department ='IT'或Department ='Marketing'

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

在Firebase for android中，我不想多次调用，只希望一个请求并获取所有与where子句键匹配。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中对多个值进行过滤的唯一方法是，如果这些值位于范围。例如，您可以获得与以下值匹配的所有项目：

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")

此问题是它还匹配名称在 HR 和 Marketing ，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中都无法将多个单独的值传递到查询中。您将必须为每个值执行单独的查询并将其合并到客户端。

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.

另请参见：

• 等同于（where）中sql的firebase

• firebase equivalent to sql where in ()

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