If you’re using Expo with React Native, SQLite, and TypeORM, you might encounter an error like:

[TypeError: _this3.sqlite.openDatabase is not a function (it is undefined)]

This error typically occurs when the expo-sqlite driver is not properly loaded or recognized by TypeORM. Here’s how to resolve it and ensure your SQLite database integration works correctly.

Problem Overview

The error arises from the following code:

import { DataSource } from 'typeorm';
import { UserEntity } from './models';

export const source = new DataSource({
  database: 'finance.db',
  type: 'expo',
  driver: require('expo-sqlite'),
  entities: [UserEntity],
  synchronize: true,
});
Source Code Cause Error
Source Code Cause Error

In this snippet, TypeORM is attempting to use expo-sqlite as the database driver. However, the error [TypeError: _this3.sqlite.openDatabase is not a function] indicates that the openDatabase method is undefined or not correctly referenced.

Solution: Update Your SQLite Import

To resolve this issue, you’ll need to explicitly import the expo-sqlite module and ensure it is properly referenced in your TypeORM DataSource configuration.

Here’s how you can fix the issue by updating the import and configuration:

import { DataSource } from 'typeorm';
import { UserEntity } from './models';

import * as SQLite from 'expo-sqlite/legacy'; // Correct import for SQLite

export const source = new DataSource({
  database: 'finance.db',
  type: 'expo',
  driver: SQLite, // Use the SQLite driver correctly
  entities: [UserEntity],
  synchronize: true,
});

Steps to Resolve the Error

  1. Install expo-sqlite if not already installed: If you haven’t installed expo-sqlite yet, run the following command:
   expo install expo-sqlite
  1. Modify the import for SQLite: Instead of using require('expo-sqlite'), switch to importing the module directly from 'expo-sqlite/legacy'. This ensures compatibility with TypeORM’s driver configuration.
   import * as SQLite from 'expo-sqlite/legacy';
  1. Update the DataSource configuration: Ensure that the driver field in your DataSource configuration uses the correct SQLite import.
   driver: SQLite,
  1. Test the Changes: After making these changes, run your Expo project to confirm the issue has been resolved.
   expo start

Why This Fix Works

The error occurred because TypeORM expected the openDatabase function to exist on the driver, but the require statement didn’t load it correctly. By explicitly importing expo-sqlite using * as SQLite from 'expo-sqlite/legacy', you ensure that TypeORM can access the correct SQLite API, preventing the undefined function error.

Conclusion

When integrating SQLite with Expo and TypeORM, you may encounter issues due to how the SQLite module is referenced. By following the steps above and ensuring the proper import of expo-sqlite, you can resolve the [TypeError: _this3.sqlite.openDatabase is not a function] error and successfully use SQLite in your Expo project.

If you’re still facing issues, ensure that your TypeORM and SQLite versions are compatible and up to date, as library updates may introduce breaking changes.

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