[null,null,["最后更新时间 (UTC)：2025-08-16。"],[],[],null,["# Get Started with Firebase Realtime Database for C++\n\n\u003cbr /\u003e\n\nThe Firebase Realtime Database stores and synchronizes data using a NoSQL cloud\ndatabase. Data is synchronized across all clients in realtime, and remains\navailable when your app goes offline.\n\nBefore You Begin\n----------------\n\nBefore you can use\n[Firebase Realtime Database](/docs/reference/unity/namespace/firebase/database),\nyou need to:\n\n- Register your C++ project and configure it to use Firebase.\n\n If your C++ project already uses Firebase, then it's already registered and\n configured for Firebase.\n- Add the [Firebase C++ SDK](/download/cpp) to your C++ project.\n\n| **Find detailed instructions for these initial\n| setup tasks in\n| [Add Firebase to your C++\n| project](/docs/cpp/setup#note-select-platform).**\n\nNote that adding Firebase to your C++ project involves tasks both in the\n[Firebase console](//console.firebase.google.com/) and in your open C++ project (for example, you download\nFirebase config files from the console, then move them into your C++ project).\n\nCreate a Database\n-----------------\n\n1. Navigate to the **Realtime Database** section of the\n [Firebase console](https://console.firebase.google.com/project/_/database).\n You'll be prompted to select an existing Firebase project.\n Follow the database creation workflow.\n\n2. Select a starting mode for your Firebase Security Rules:\n\n Test mode\n\n : Good for getting started with the mobile and web client libraries,\n but allows anyone to read and overwrite your data. After testing, **make\n sure to review the [Understand Firebase Realtime Database Rules](/docs/database/security)\n section.**\n\n :\n | **Note:** If you create a database in Test mode and make no changes to the default world-readable and world-writeable Rules within a trial period, you will be alerted by email, then your database rules will deny all requests. Note the expiration date during the Firebase console setup flow.\n\n : To get started with the web, Apple, or Android SDK, select testmode.\n\n Locked mode\n\n : Denies all reads and writes from mobile and web clients.\n Your authenticated application servers can still access your database.\n\n3. Choose a location for the database.\n\n Depending on the\n [location of the database](/docs/projects/locations#rtdb-locations), the\n URL for the new database will be in one of the following forms:\n - \u003cvar translate=\"no\"\u003eDATABASE_NAME\u003c/var\u003e`.firebaseio.com` (for\n databases in `us-central1`)\n\n - \u003cvar translate=\"no\"\u003eDATABASE_NAME\u003c/var\u003e`.`\u003cvar translate=\"no\"\u003eREGION\u003c/var\u003e`.firebasedatabase.app`\n (for databases in all other locations)\n\n4. Click **Done**.\n\nWhen you enable Realtime Database, it also enables the API in the\n[Cloud API Manager](https://console.cloud.google.com/projectselector/apis/api/firebasedatabase.googleapis.com/overview).\n\nCreate and Initialize firebase::App\n-----------------------------------\n\nBefore you can access the Realtime Database, you'll need to create and initialize the\n[`firebase::App`](/docs/reference/cpp/class/firebase/app).\n| You only need to initialize firebase::App once, no matter how many Firebase C++ features you use.\n\nInclude the header file for `firebase::App`: \n\n```c++\n#include \"firebase/app.h\"\n``` \n\n### Android\n\n\nCreate the `firebase::App`, passing the JNI environment and a `jobject`\nreference to the Java Activity as arguments: \n\n```c++\napp = ::firebase::App::Create(::firebase::AppOptions(\"APPLICATION NAME\"), jni_env, activity);\n```\n\n### iOS+\n\n\nCreate the `firebase::App`: \n\n```c++\napp = ::firebase::App::Create(::firebase::AppOptions(\"APPLICATION NAME\"));\n```\n\nAccess the firebase::database::Database Class\n---------------------------------------------\n\nThe [`firebase::database::Database`](/docs/reference/cpp/class/firebase/database/database)\nis the entry point for the Firebase Realtime Database C++ SDK. \n\n```c++\n::firebase::database::Database *database = ::firebase::database::Database::GetInstance(app);\n```\n\nIf you have chosen to use public access for your rules, you can proceed to the\nsections on saving and retrieving data.\n\nSetting up Restricted Access\n----------------------------\n\nIf you do not want to use public access you can add Firebase Authentication to your\napp to control access to the database.\n\nNext Steps\n----------\n\n- Learn how to [structure data](/docs/database/cpp/structure-data) for Realtime Database.\n\n- [Scale your data across multiple database\n instances.](/docs/database/usage/sharding)\n\n- [Save data.](/docs/database/cpp/save-data)\n\n- [Retrieve data.](/docs/database/cpp/retrieve-data)\n\n- [View your database in the\n Firebase console.](//console.firebase.google.com/project/_/database/data)\n\n- Prepare to launch your app:\n\n\n - Set up [budget\n alerts](/docs/projects/billing/avoid-surprise-bills#set-up-budget-alert-emails) for your project in the Google Cloud console.\n - Monitor the [*Usage and billing*\n dashboard](//console.firebase.google.com/project/_/usage) in the Firebase console to get an overall picture of your project's usage across multiple Firebase services. You can also visit the [Realtime Database *Usage*\n dashboard](//console.firebase.google.com/project/_/database/usage) for more detailed usage information.\n - Review the [Firebase launch checklist](/support/guides/launch-checklist).\n\nKnown Issues\n------------\n\n- On desktop platforms (Windows, Mac, Linux), the Firebase C++ SDK uses REST to access your database. Because of this, you must [declare the indexes you use](https://firebase.google.com/docs/database/security/#section-defining-indexes) with Query::OrderByChild() on desktop or your listeners will fail.\n- The desktop workflow version of Realtime Database does not support offline or persistence."]]
