Python-Google Firebase中的复杂查询 [英] Python - Complex Query in Google Firebase

问题描述

我有一个如下所示的数据库

I have a database which is shown in below

我只想按顺序显示全名.我想要该输出:

I want to show only the full_names in order. I want that output:

Alan Turing
Alan Turing
Alan Turing
Alan Turing
Alan Turing

我在下面尝试了此代码，但显示了用户名.

I tried with this code below but it shows the user names.

import firebase_admin
from firebase_admin import credentials
from firebase_admin import db

# Fetch the service account key JSON file contents
cred = credentials.Certificate('BLABLA.json')
# Initialize the app with a service account, granting admin privileges
firebase_admin.initialize_app(cred, {
    'databaseURL': 'https://BLABLA.firebaseio.com/'
})

ref = db.reference('users')
snapshot = ref.order_by_child('full_name').get()
for key in snapshot:
    print(key)

输出为:

alanisawesom
alanisawesome
alanisawesomee
alanisawesomeee
alanisawesomeeee

我的错在哪里?你能解决吗?

Where is my fault? Can you fix it?

我在Firebase中的规则是:

{
  "rules": {
    "users": {
      ".indexOn": ["date_of_birth", "full_name"]
    },
    ".read": "true",
    ".write": "true"
  }
}

推荐答案

您的查询告诉数据库返回 users 下按其 full_name 属性排序的节点.但是Firebase仍会返回完整的节点，而不仅仅是返回您要求订购的属性.

Your query tells the database to return the nodes under users ordered by their full_name property. But Firebase still returns the full nodes, not just the property you told it to order on.

要仅显示每个节点的 full_name ，您需要从结果中的每个子节点获取该属性.像这样:

To only display the full_name of each node, you need to get that property from each child node in the result. Something like this:

ref = db.reference('users')
snapshot = ref.order_by_child('full_name').get()
for user in snapshot.each():
    print(user.child("full_name").val())

我不是Pythonista，所以我在这里寻求语法帮助:

I'm not a Pythonista, so I looked here for help on syntax: How to loop through each firebase database child with python?

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