31.11. Data Persistence with SQLite in Flutter: Data Backup and Restore

Data persistence is a crucial aspect of application development. When building an app using Flutter and Dart, one of the available options for persisting data is SQLite, an embedded SQL database engine. In this chapter of our e-book course, we'll explore how to implement data persistence with SQLite in Flutter, with a special focus on performing data backup and restore.

SQLite in Flutter

SQLite is a C language library that provides a lightweight, disk-based database that does not require a separate server process and allows you to access the database using a non-standard variant of the SQL query language. With the SQLite package in Flutter, you can easily manipulate SQLite databases.

Adding the SQLite dependency

To start using SQLite in your Flutter project, you need to add the dependency. In sqflite pub file: ^2.0.0+3

dependencies:
  flutter:
    sdk: flutter
>

Then run 'flutter packages get' in the terminal to download the dependency.

Creating the SQLite database

To create an SQLite database, you need to define the database path and version, and then call the openDatabase() function. The openDatabase() function receives as parameters the path and version of the database, and an onCreate callback that is called if the database does not already exist.

Data backup

To back up SQLite data, you need to copy the SQLite database file to a safe location. SQLite stores all data in a single database file. So, to take the backup, you can simply copy the database file to another location. You can do this using the 'path_provider' library to get the document directory path and the 'dart:io' library to copy the file.

Data Restoration

To restore data, you need to copy the backup file to the original location. You can do this again using the 'path_provider' library to get the document directory path and the 'dart:io' library to copy the file back. After copying the file back, you need to reopen the database for the changes to be reflected.

Conclusion

Data persistence is an important aspect of application development, and SQLite provides a robust and lightweight solution for this. In this chapter, we explore how to implement data persistence with SQLite in Flutter, how to backup and restore data. In the next chapter, we'll explore how to use SQLite to perform CRUD (Create, Read, Update, Delete) operations.

In conclusion, SQLite is a powerful tool for persisting data in Flutter applications. With it, you can store data locally on the user's device, allowing your app to work even offline. Additionally, the ability to back up and restore data can be crucial to preventing data loss and ensuring continuity of service for your users.

We hope you found this chapter informative and useful for your learning. Please feel free to contact us if you have any questions or comments. We look forward to seeing you in the next chapter!