Firebase创建安全规则以仅允许获取查询大小

{
  "users": {
    "userId1": {
      "name": "Alice",
      "email": "alice@example.com"
    },
    "userId2": {
      "name": "Bob",
      "email": "bob@example.com"
    }
  }
}

{
  "rules": {
    "users": {
      "$uid": {
        ".read": "auth != null && request.auth.uid == $uid",
        ".write": "auth != null && request.auth.uid == $uid"
      }
    }
  }
}

import firebase from 'firebase/app';
import 'firebase/database';

// 初始化 Firebase
const firebaseConfig = {
  // 你的 Firebase 配置
};

firebase.initializeApp(firebaseConfig);

const database = firebase.database();

// 获取查询大小
const usersRef = database.ref('users');
usersRef.once('value', (snapshot) => {
  const size = snapshot.numChildren();
  console.log(`查询大小: ${size}`);
});

usersRef.once('value', (snapshot) => {
  const size = snapshot.numChildren();
  console.log(`查询大小: ${size}`);
}).catch((error) => {
  console.error("获取查询大小失败:", error);
});