Firebase querying with partial string match [dupli

问题:

This question already has answers here:

How to do a simple search in string in Firebase database? (6 answers)

Closed 2 years ago.

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%'

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.

回答1:

According to the doc of Java Admin you can do something like this it should also work with Android

For data starting with abc,

yourRef.orderByKey().startAt("abc").endAt("abc\uf8ff")

The \uf8ff is after most regular characters in Unicode, so the query should matches all values that start with a abc.