使用部分字符串匹配进行Firebase查询 [英] Firebase querying with partial string match
问题描述
假设我有一个简单的firebase实时数据库结构，其中的键为username，值为userid.现在，我要按username搜索userid.如果用户名匹配，这是非常容易的.但是如何获得部分匹配的答案.更明确的是，如果我要使用SQL编写此代码，将类似于:
Suppose I have a simple firebase realtime database structure where the key is username and the value is userid. Now I want to search userid by username. It is quite easy if the username matches. but how to get the answer for partial match. To be more clear if i were to write this using SQL it would be something like:
SELECT userid
FROM tablename
WHERE username LIKE 'abc%'
SELECT userid
FROM tablename
WHERE username LIKE 'abc%'
它将为我提供所有userid，其中username以abc开头.
如何编写此类针对Firebase的查询?了解我在android设备上使用它，并且可能有很多用户.
it will give me all the userid where the username starts with abc.
How to write this type of query for firebase? Understand i am using this on a android device and there can be a lot of user.
推荐答案
根据Java Admin的文档，您可以执行类似的操作，它也应与Android一起使用
According to the doc of Java Admin you can do something like this it should also work with Android
对于以abc开头的数据，
yourRef.orderByKey().startAt("abc").endAt("abc\uf8ff")
\ uf8ff在Unicode中大多数常规字符之后，因此查询应匹配以abc开头的所有值.
The \uf8ff is after most regular characters in Unicode, so the query should matches all values that start with a abc.
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