Expo Docs MCP Server

--- title: SQLite (legacy) description: A library that provides access to a database that can be queried through a WebSQL-like API. sourceCodeUrl: https://github.com/expo/expo/tree/sdk-51/packages/expo-sqlite packageName: expo-sqlite iconUrl: /static/images/packages/expo-sqlite.png platforms: ["android", "ios"] --- `expo-sqlite` gives your app access to a database that can be queried through a [WebSQL](https://www.w3.org/TR/webdatabase/)-like API. The database is persisted across restarts of your app. ## Installation ## Usage ### Importing an existing database To open a new SQLite database using an existing `.db` file you already have, follow the steps below: Install `expo-file-system` and `expo-asset` modules: Create a **metro.config.js** file at the root of your project with the following contents to include [extra asset extensions](/guides/customizing-metro/#adding-more-file-extensions-to--assetexts): ```js const { getDefaultConfig } = require('expo/metro-config'); const defaultConfig = getDefaultConfig(__dirname); defaultConfig.resolver.assetExts.push('db'); module.exports = defaultConfig; ``` Use the following function (or similar) to open your database: ```ts async function openDatabase(pathToDatabaseFile: string): Promise<SQLite.SQLiteDatabase> { if (!(await FileSystem.getInfoAsync(FileSystem.documentDirectory + 'SQLite')).exists) { await FileSystem.makeDirectoryAsync(FileSystem.documentDirectory + 'SQLite'); } const asset = await Asset.fromModule(require(pathToDatabaseFile)).downloadAsync(); await FileSystem.copyAsync({ from: asset.localUri, to: FileSystem.documentDirectory + 'SQLite/myDatabaseName.db', }); return SQLite.openDatabase('myDatabaseName.db'); } ``` ### Executing statements with an async transaction ```js const db = SQLite.openDatabase('dbName', version); const readOnly = true; await db.transactionAsync(async tx => { const result = await tx.executeSqlAsync('SELECT COUNT(*) FROM USERS', []); console.log('Count:', result.rows[0]['COUNT(*)']); }, readOnly); ``` ### Executing statements outside of a transaction > You should use this kind of execution only when it is necessary. For instance, when code is a no-op within transactions. Example: `PRAGMA foreign_keys = ON;`. ```js const db = SQLite.openDatabase('dbName', version); await db.execAsync([{ sql: 'PRAGMA foreign_keys = ON;', args: [] }], false); console.log('Foreign keys turned on'); ``` ## API ```js ```