Firebase数据库搜索查询 [英] Firebase Database Search Query

问题描述

我正在尝试使用字符串(例如"A")搜索数据库.我只是在看此Firebase教程已为Firebase数据库转换的通用SQL查询-Firebase对于SQL Developers#4的数据库，它解释说，为了在数据库中搜索字符串(在特定位置)，必须使用:

I am trying to search my database using a string, such as "A". I was just watching this Firebase tutorial Common SQL Queries converted for the Firebase Database - The Firebase Database For SQL Developers #4 and it explains that, in order to search the database for a string (in a certain location), you must use:

firebase.database().ref.child("child_name_here")
    .queryOrdered(byChild: "child_name_here")
    .queryStarting(atValue: "value_here_uppercase")
    .queryEnding(atValue: "value_here_uppercase\\uf8ff")

为了获得一个\，必须在结束值中使用两个\\作为转义字符.

You must use two \\ in the ending value as an escape character in order to get one \.

当我在Firebase数据库中尝试此操作时，它不起作用.这是我的数据库:

When I try this with my Firebase database, it does not work. Here is my database:

{
    "Schools": {
        "randomUID": {
            "location" : "anyTown, anyState",
            "name" : "anyName"
        }
    }
}

这是我的查询:

databaseReference.child("Schools")
    .queryOrdered(byChild: "name")
    .queryStarting(atValue: "A")
    .queryEnding(atValue: "A\\uf8ff") ...

当我从Firebase打印快照时，我回来了.

When I go to print the snapshot from Firebase, I get back.

如果我删除了结尾.queryEnding(atValue: "A\\uf8ff")，则数据库将返回Schools节点中的所有学校.

If I get rid of the ending .queryEnding(atValue: "A\\uf8ff"), the database returns all of the schools in the Schools node.

如何使用字符串搜索Firebase数据库?

推荐答案

这将显示与Wick匹配的所有客户. (不是很快，但可能会给您一个想法)

This shows all customers that match Wick. (It's not swift but may give you an idea)

// sample
let query = 'Wick' 
clientsRef.orderByChild('name')
.startAt(query)
.endAt(query + '\uf8ff')
.once('value', (snapshot) => {
     ....        
})

这篇关于Firebase数据库搜索查询的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！