{"componentChunkName":"component---src-templates-documentation-tsx","path":"/database/usage","result":{"data":{"mdx":{"body":"var _excluded = [\"components\"];\nfunction _extends() { _extends = Object.assign ? Object.assign.bind() : function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; }; return _extends.apply(this, arguments); }\nfunction _objectWithoutProperties(source, excluded) { if (source == null) return {}; var target = _objectWithoutPropertiesLoose(source, excluded); var key, i; if (Object.getOwnPropertySymbols) { var sourceSymbolKeys = Object.getOwnPropertySymbols(source); for (i = 0; i < sourceSymbolKeys.length; i++) { key = sourceSymbolKeys[i]; if (excluded.indexOf(key) >= 0) continue; if (!Object.prototype.propertyIsEnumerable.call(source, key)) continue; target[key] = source[key]; } } return target; }\nfunction _objectWithoutPropertiesLoose(source, excluded) { if (source == null) return {}; var target = {}; var sourceKeys = Object.keys(source); var key, i; for (i = 0; i < sourceKeys.length; i++) { key = sourceKeys[i]; if (excluded.indexOf(key) >= 0) continue; target[key] = source[key]; } return target; }\n/* @jsxRuntime classic */\n/* @jsx mdx */\n\nvar _frontmatter = {\n  \"title\": \"Realtime Database\",\n  \"description\": \"Installation and getting started with Realtime Database.\",\n  \"icon\": \"//firebase.google.com/static/images/products/icons/build_realtime_database.svg\",\n  \"next\": \"/database/offline-support\",\n  \"previous\": \"/crashlytics/crash-reports\"\n};\nvar makeShortcode = function makeShortcode(name) {\n  return function MDXDefaultShortcode(props) {\n    console.warn(\"Component \" + name + \" was not imported, exported, or provided by MDXProvider as global scope\");\n    return mdx(\"div\", props);\n  };\n};\nvar Youtube = makeShortcode(\"Youtube\");\nvar layoutProps = {\n  _frontmatter: _frontmatter\n};\nvar MDXLayout = \"wrapper\";\nreturn function MDXContent(_ref) {\n  var components = _ref.components,\n    props = _objectWithoutProperties(_ref, _excluded);\n  return mdx(MDXLayout, _extends({}, layoutProps, props, {\n    components: components,\n    mdxType: \"MDXLayout\"\n  }), mdx(\"h1\", {\n    \"id\": \"installation\"\n  }, \"Installation\"), mdx(\"p\", null, \"This module requires that the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"@react-native-firebase/app\"), \" module is already setup and installed. To install the \\\"app\\\" module, view the\\n\", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"/\"\n  }, \"Getting Started\"), \" documentation.\"), mdx(\"pre\", {\n    \"className\": \"language-bash\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-bash\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token comment\"\n  }, \"# Install & setup the app module\"), \"\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"yarn\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"add\"), \" @react-native-firebase/app\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token comment\"\n  }, \"# Install the database module\"), \"\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"yarn\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"add\"), \" @react-native-firebase/database\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token comment\"\n  }, \"# If you're developing your app using iOS, run this command\"), \"\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token builtin class-name\"\n  }, \"cd\"), \" ios/ \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"&&\"), \" pod \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"install\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"&&\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token builtin class-name\"\n  }, \"cd\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"..\"), \"\\n\")), mdx(\"p\", null, \"If you're using an older version of React Native without autolinking support, or wish to integrate into an existing project,\\nyou can follow the manual installation steps for \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"/database/usage/installation/ios\"\n  }, \"iOS\"), \" and \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"/database/usage/installation/android\"\n  }, \"Android\"), \".\"), mdx(\"h1\", {\n    \"id\": \"what-does-it-do\"\n  }, \"What does it do\"), mdx(\"p\", null, \"The Realtime Database is a cloud-hosted database. Data is stored as JSON and synchronized in realtime to every connected\\nclient. React Native Firebase provides native integration with the Android & iOS Firebase SDKs, supporting both realtime\\ndata sync and offline capabilities.\"), mdx(Youtube, {\n    id: \"U5aeM5dvUpA\",\n    mdxType: \"Youtube\"\n  }), mdx(\"p\", null, \"To learn more, view the \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"https://firebase.google.com/docs/database?utm_source=invertase&utm_medium=react-native-firebase&utm_campaign=database\"\n  }, \"Firebase Realtime Database documentation\"), \".\"), mdx(\"h1\", {\n    \"id\": \"usage\"\n  }, \"Usage\"), mdx(\"h2\", {\n    \"id\": \"references\"\n  }, \"References\"), mdx(\"p\", null, \"A core concept to understanding Realtime Database are references - a reference to a specific node within your database. A node\\ncan be a specific property or sub-nodes.\"), mdx(\"p\", null, \"To create a \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"/reference/database/reference\"\n  }, mdx(\"inlineCode\", {\n    parentName: \"a\"\n  }, \"Reference\")), \", call the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"ref\"), \" method:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"import\"), \" database \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"from\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'@react-native-firebase/database'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"const\"), \" reference \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"=\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'/users/123'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"p\", null, \"NOTE: To get a reference to a database other than a 'us-central1' default database, you must pass the database URL. 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\"'https://<databaseName>.<region>.firebasedatabase.app/'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'/users/123'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"h2\", {\n    \"id\": \"reading-data\"\n  }, \"Reading data\"), mdx(\"p\", null, \"The Realtime Data provides the ability to read the value of a reference as a one-time read, or realtime changes to the node.\\nWhen a value is read from the database, the API returns a \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"/reference/database/datasnapshot\"\n  }, mdx(\"inlineCode\", {\n    parentName: \"a\"\n  }, \"DataSnapshot\")), \".\"), mdx(\"p\", null, \"The snapshot includes information such as whether the reference node exists, it's value or any children the node has and more.\"), mdx(\"h3\", {\n    \"id\": \"one-time-read\"\n  }, \"One-time read\"), mdx(\"p\", null, \"To read the value once, call the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"once\"), \" method on a reference:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"import\"), \" database \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"from\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'@react-native-firebase/database'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'/users/123'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"once\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'value'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"then\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token parameter\"\n  }, \"snapshot\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token arrow operator\"\n  }, \"=>\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n    \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token console class-name\"\n  }, \"console\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"log\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'User data: '\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" snapshot\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"val\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"h3\", {\n    \"id\": \"realtime-changes\"\n  }, \"Realtime changes\"), mdx(\"p\", null, \"To setup an active listener to react to any changes to the node and it's children, call the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"on\"), \" method with an event handler:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"import\"), \" database \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"from\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'@react-native-firebase/database'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'/users/123'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"on\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    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string\"\n  }, \"'User data: '\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" snapshot\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"val\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"p\", null, \"The event handler will be called straight away with the snapshot data, and further called when any changes to the node\\noccur.\"), mdx(\"p\", null, \"You can unsubscribe from events by calling the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"off\"), \" method. To unsubscribe from specific events, call the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"off\"), \" method\\nwith the function that the event handler returned. This can be used within any \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"useEffect\"), \" hooks to automatically unsubscribe\\nwhen the hook needs to unsubscribe itself:\"), mdx(\"pre\", {\n    \"className\": \"language-jsx\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-jsx\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"import\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token maybe-class-name\"\n  }, \"React\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \" useEffect \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"from\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'react'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"import\"), \" database \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"from\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'@react-native-firebase/database'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"function\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token maybe-class-name\"\n  }, \"User\")), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token parameter\"\n  }, mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \" userId \", mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token punctuation\"\n  }, \"}\")), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"useEffect\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token arrow operator\"\n  }, \"=>\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n    \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"const\"), \" onValueChange \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"=\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n      \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token template-string\"\n  }, mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token template-punctuation string\"\n  }, \"`\"), mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token string\"\n  }, \"/users/\"), mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token interpolation\"\n  }, mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token interpolation-punctuation punctuation\"\n  }, \"${\"), \"userId\", mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token interpolation-punctuation punctuation\"\n  }, \"}\")), mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token template-punctuation string\"\n  }, \"`\")), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n      \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"on\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'value'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token parameter\"\n  }, \"snapshot\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token arrow operator\"\n  }, \"=>\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n        \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token console class-name\"\n  }, \"console\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"log\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'User data: '\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" snapshot\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"val\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n      \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n    \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token comment\"\n  }, \"// Stop listening for updates when no longer required\"), \"\\n    \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"return\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token arrow operator\"\n  }, \"=>\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token template-string\"\n  }, mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token template-punctuation string\"\n  }, \"`\"), mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token string\"\n  }, \"/users/\"), mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token interpolation\"\n  }, mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token interpolation-punctuation punctuation\"\n  }, \"${\"), \"userId\", mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token interpolation-punctuation punctuation\"\n  }, \"}\")), mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token template-punctuation string\"\n  }, \"`\")), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"off\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'value'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" onValueChange\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"[\"), \"userId\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"]\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), \"\\n\")), mdx(\"h4\", {\n    \"id\": \"additional-events\"\n  }, \"Additional events\"), mdx(\"p\", null, \"The above example demonstrates how to subscribe to events whenever a value within the node changes. In some cases, you\\nmay need to only subscribe to events whenever a child node is added/changed/moved/removed. This can be achieved by passing\\na different \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"/reference/database/eventtype\"\n  }, mdx(\"inlineCode\", {\n    parentName: \"a\"\n  }, \"EventType\")), \" to the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"on\"), \" method.\"), mdx(\"p\", null, \"If you are listening to a node with many children, only listening to data you care about helps reduce network bandwidth\\nand speeds up your application.\"), mdx(\"pre\", {\n    \"className\": \"language-jsx\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-jsx\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"import\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token maybe-class-name\"\n  }, \"React\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \" useEffect \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"from\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'react'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"import\"), \" database \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"from\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'@react-native-firebase/database'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"function\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token maybe-class-name\"\n  }, \"User\")), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token parameter\"\n  }, mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \" userId \", mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token punctuation\"\n  }, \"}\")), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"useEffect\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token arrow operator\"\n  }, \"=>\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n    \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"const\"), \" onChildAdd \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"=\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n      \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'/users'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n      \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"on\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'child_added'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token parameter\"\n  }, \"snapshot\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token arrow operator\"\n  }, \"=>\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n        \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token console class-name\"\n  }, \"console\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"log\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'A new node has been added'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" snapshot\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"val\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n      \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n    \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token comment\"\n  }, \"// Stop listening for updates when no longer required\"), \"\\n    \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"return\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token arrow operator\"\n  }, \"=>\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'/users'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"off\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'child_added'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" onChildAdd\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"[\"), \"userId\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"]\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), \"\\n\")), mdx(\"h3\", {\n    \"id\": \"querying\"\n  }, \"Querying\"), mdx(\"p\", null, \"Realtime Database provides support for basic querying of your data. When a reference node contains children, you can both\\norder & limit the returned results.\"), mdx(\"p\", null, \"If your application requires more advanced query capabilities, it is recommended you use \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"/firestore\"\n  }, \"Cloud Firestore\"), \".\"), mdx(\"h4\", {\n    \"id\": \"ordering\"\n  }, \"Ordering\"), mdx(\"p\", null, \"By default, results are ordered based on the node \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"#database-keys\"\n  }, \"keys\"), \". If however you are using custom keys you can use\\none of the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"orderByX\"), \" methods to order your data.\"), mdx(\"p\", null, \"For example, if all of the nodes children are scalar values (string, number or boolean) you can use the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"orderByValue\"), \" method,\\nand Firebase will automatically order the results. The example below would return the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"def\"), \" node before the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"abc\"), \" node:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token comment\"\n  }, \"/*\\n * {\\n *   'scores': {\\n *     'abc: 30,\\n *     'def': 50,\\n *   }\\n * }\\n */\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"const\"), \" scores \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"=\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'scores'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"orderByValue\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"once\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'value'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"p\", null, \"Please note that the ordering will not be respected if you do not use the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"forEach\"), \" method provided on the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"DataSnapshot\"), \".\"), mdx(\"h4\", {\n    \"id\": \"limiting\"\n  }, \"Limiting\"), mdx(\"p\", null, \"You can limit the number of results returned from a query by using one of the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"limitToX\"), \" methods. For example, to limit to the\\nfirst 10 results:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"const\"), \" users \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"=\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'users'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"limitToFirst\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token number\"\n  }, \"10\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"once\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'value'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"p\", null, \"Firebase also provides the ability to return the last set of results in a query via the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"limitToLast\"), \" method.\"), mdx(\"p\", null, \"Instead of limiting to a specific number of documents, you can also start from, or end at a specific reference node value:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"await\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'users'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"orderByChild\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'age'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"startAt\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token number\"\n  }, \"21\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"once\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'value'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"h2\", {\n    \"id\": \"writing-data\"\n  }, \"Writing data\"), mdx(\"p\", null, \"The \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"https://firebase.google.com/docs/database/web/structure-data\"\n  }, \"Firebase documentation\"), \" provides great examples on best\\npractices on how to structure your data. We highly recommend reading the guide before building out your database.\"), mdx(\"h3\", {\n    \"id\": \"setting-data\"\n  }, \"Setting data\"), mdx(\"p\", null, \"The \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"set\"), \" method on a \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"/reference/database/reference\"\n  }, mdx(\"inlineCode\", {\n    parentName: \"a\"\n  }, \"Reference\")), \" overwrites all of the existing data at that reference node.\\nThe value can be anything; a string, number, object etc:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"import\"), \" database \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"from\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'@react-native-firebase/database'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'/users/123'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"set\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n    name\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \":\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'Ada Lovelace'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \"\\n    age\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \":\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token number\"\n  }, \"31\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"then\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token arrow operator\"\n  }, \"=>\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token console class-name\"\n  }, \"console\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"log\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'Data set.'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"p\", null, \"If you set the value to \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"null\"), \", Firebase will automatically class the node as removed, and delete it from the database.\"), mdx(\"h3\", {\n    \"id\": \"updating-data\"\n  }, \"Updating data\"), mdx(\"p\", null, \"Rather than overwriting all existing data, the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"update\"), \" method provides the ability to update any existing data on the reference node.\\nFirebase will automatically merge the data depending on what currently exists.\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"import\"), \" database \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"from\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'@react-native-firebase/database'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'/users/123'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"update\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n    age\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \":\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token number\"\n  }, \"32\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"then\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token arrow operator\"\n  }, \"=>\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token console class-name\"\n  }, \"console\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"log\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'Data updated.'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"h3\", {\n    \"id\": \"pushing-data\"\n  }, \"Pushing data\"), mdx(\"p\", null, \"Currently the examples have only demonstrated working with known reference node keys (e.g. \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"/users/123\"), \"). In some cases,\\nyou may not have a suitable id or may want Firebase to automatically create a node with a generated key. The \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"push\"), \" method\\nreturns a \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"/reference/database/thenablereference\"\n  }, mdx(\"inlineCode\", {\n    parentName: \"a\"\n  }, \"ThenableReference\")), \", allowing you to observe a node before it is\\nsent to remote Firebase database.\"), mdx(\"p\", null, \"The \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"push\"), \" method will automatically generate a new key if one is not provided:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"const\"), \" newReference \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"=\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'/users'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"push\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token console class-name\"\n  }, \"console\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"log\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'Auto generated key: '\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" newReference\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token property-access\"\n  }, \"key\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\nnewReference\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"set\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n    age\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \":\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token number\"\n  }, \"32\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"then\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token arrow operator\"\n  }, \"=>\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token console class-name\"\n  }, \"console\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"log\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'Data updated.'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"p\", null, \"The keys generated are ordered to the current time, so the list of items returned from Firebase will be chronologically\\nsorted by default.\"), mdx(\"h2\", {\n    \"id\": \"removing-data\"\n  }, \"Removing data\"), mdx(\"p\", null, \"To remove data, you can call the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"remove\"), \" method on a reference:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"await\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'/users/123'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"remove\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"p\", null, \"Optionally, you can also set the value of a reference node to \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"null\"), \" to remove it from the database:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"await\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'/users/123'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"set\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword null nil\"\n  }, \"null\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"h2\", {\n    \"id\": \"transactions\"\n  }, \"Transactions\"), mdx(\"p\", null, \"Transactions are a way to always ensure a write occurs with the latest information available on the server. Transactions never\\npartially apply writes & all writes execute at the end of a successful transaction.\"), mdx(\"p\", null, \"Imagine a scenario whereby an app has the ability to \\\"Like\\\" user posts. Whenever a user presses the \\\"Like\\\" button,\\nthe \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"/likes/:postId\"), \" value (number of likes) on the database increments. Without transactions, we'd first need to\\nread the existing value and then increment that value in two separate operations.\"), mdx(\"p\", null, \"On a high traffic application, the value on the server could already have changed by the time the operation sets a new value,\\ncausing the actual number to not be consistent.\"), mdx(\"p\", null, \"Transactions remove this issue by atomically updating the value on the server. If the value changes whilst the transaction\\nis executing, it will retry. This always ensures the value on the server is used rather than the client value.\"), mdx(\"p\", null, \"To execute a new transaction, call the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"transaction\"), \" method on a reference:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"import\"), \" database \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"from\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'@react-native-firebase/database'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"function\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"onPostLike\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token parameter\"\n  }, \"postId\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"const\"), \" reference \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"=\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token template-string\"\n  }, mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token template-punctuation string\"\n  }, \"`\"), mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token string\"\n  }, \"/likes/\"), mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token interpolation\"\n  }, mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token interpolation-punctuation punctuation\"\n  }, \"${\"), \"postId\", mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token interpolation-punctuation punctuation\"\n  }, \"}\")), mdx(\"span\", {\n    parentName: \"span\",\n    \"className\": \"token template-punctuation string\"\n  }, \"`\")), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token comment\"\n  }, \"// Execute transaction\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"return\"), \" reference\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"transaction\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token parameter\"\n  }, \"currentLikes\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token arrow operator\"\n  }, \"=>\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n    \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"if\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), \"currentLikes \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"===\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword null nil\"\n  }, \"null\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"return\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token number\"\n  }, \"1\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n    \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"return\"), \" currentLikes \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"+\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token number\"\n  }, \"1\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token comment\"\n  }, \"// When post \\\"567\\\" is liked\"), \"\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"onPostLike\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'567'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"then\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token parameter\"\n  }, \"transaction\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token arrow operator\"\n  }, \"=>\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \"\\n  \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token console class-name\"\n  }, \"console\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"log\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'New post like count: '\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" transaction\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token property-access\"\n  }, \"snapshot\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"val\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"p\", null, \"Once the transaction is successful, a promise is resolved with a value containing whether the operation committed on the remote\\ndatabase and the new \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"/reference/database/datasnapshot\"\n  }, mdx(\"inlineCode\", {\n    parentName: \"a\"\n  }, \"DataSnapshot\")), \" containing the new value.\"), mdx(\"h1\", {\n    \"id\": \"securing-data\"\n  }, \"Securing data\"), mdx(\"p\", null, \"It is important that you understand how to write rules in your Firebase console to ensure that your data is secure.\\nPlease follow the Firebase Realtime Database documentation on \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"https://firebase.google.com/docs/database/security\"\n  }, \"security\")), mdx(\"h1\", {\n    \"id\": \"using-a-secondary-database\"\n  }, \"Using a secondary database\"), mdx(\"p\", null, \"If the default installed Firebase instance needs to address a different database within the same project, call the database method on the default app with passing the database URL.\\nFor example:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"import\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \" firebase \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"from\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'@react-native-firebase/database'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"const\"), \" database \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"=\"), \" firebase\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"app\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'https://path-to-database.firebaseio.com'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\ndatabase\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"h2\", {\n    \"id\": \"connect-to-a-database-of-a-secondary-app\"\n  }, \"Connect to a database of a secondary app\"), mdx(\"p\", null, \"If you want to address a database from a different Firebase project, you will need to create a secondary app first\\n(Read more on creating a secondary app here: \", mdx(\"a\", {\n    parentName: \"p\",\n    \"href\": \"https://rnfirebase.io/app/usage\"\n  }, \"https://rnfirebase.io/app/usage\"), \").\\nFor example:\"), mdx(\"pre\", {\n    \"className\": \"language-js\"\n  }, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-js\"\n  }, mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"import\"), \" database\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"{\"), \" firebase \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"}\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword module\"\n  }, \"from\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token string\"\n  }, \"'@react-native-firebase/database'\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token comment\"\n  }, \"// create a secondary app\"), \"\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"const\"), \" secondaryApp \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"=\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"await\"), \" firebase\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"initializeApp\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), \"credentials\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \",\"), \" config\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token comment\"\n  }, \"// pass the secondary app instance to the database module\"), \"\\n\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token keyword\"\n  }, \"const\"), \" secondaryDatabase \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token operator\"\n  }, \"=\"), \" \", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token function\"\n  }, \"database\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), \"secondaryApp\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\\nsecondaryDatabase\", mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \".\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token method function property-access\"\n  }, \"ref\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \"(\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \")\"), mdx(\"span\", {\n    parentName: \"code\",\n    \"className\": \"token punctuation\"\n  }, \";\"), \"\\n\")), mdx(\"h1\", {\n    \"id\": \"firebasejson\"\n  }, \"firebase.json\"), mdx(\"h2\", {\n    \"id\": \"enabling-persistence\"\n  }, \"Enabling persistence\"), mdx(\"p\", null, \"The Realtime Database can be set to persist data on the user application to be used by the SDKs for offline usage\\nand caching. 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