sqflite_common_ffi_web

sqlite Web implementation (experimental). Features:

  • Persistency (in indexeddb)
  • Cross-tab safe (runs in a shared worker)
  • Wasm compatible

Thanks Simon Binder for the excellent sqlite3 lib.

Setup

Add the dependency:

  dependencies:
    sqflite_common_ffi_web:

Setup binaries

Implementation requires sqlite3.wasm binaries into your web folder as well as a sqflite specific shared worker.

You can install binaries using the command:

$ dart run sqflite_common_ffi_web:setup

It should create the following files in your web folder:

  • sqlite3.wasm
  • sqflite_sw.js

that you can put in source control or not (personally I don't)

Note: when sqlite3 and its wasm binary are updated, you may need to run the command again using the force option:

$ dart run sqflite_common_ffi_web:setup --force

However since it depends on sqflite3 version and its associated binary, if it gets updated and the tool still download the old version (sorry it is hardcoded) you might have to manually download a compatible binary from sqlite3.wasm binaries I don't have a better option yet, sorry.

Use the proper factory.

// Use the ffi web factory in web apps (flutter or dart)
var factory = databaseFactoryFfiWeb;
var db = await factory.openDatabase('my_db.db');
var sqliteVersion = (await db.rawQuery('select sqlite_version()')).first.values.first;
print(sqliteVersion); // should print 3.39.3

Add web support to existing sqflite application

If you have any existing iOS/Android application, one solution is to change the default database factory:

import 'package:sqflite_common_ffi_web/sqflite_ffi_web.dart';
import 'package:sqflite/sqflite.dart';

var path = '/my/db/path';
if (kIsWeb) {
  // Change default factory on the web
  databaseFactory = databaseFactoryFfiWeb;
  path = 'my_web_web.db';
}

// open the database
var db = openDatabase(path);

Limitations

Use the same web port when debugging

The database is stored in the browser indexeddb. Like any other web storage, it is tied to the port. (i.e. localhost:8080 is different from localhost:8081). When debugging, you should use the same port to keep the same indexeddb database.

No shared worker available

When shared worker are not supported - for example in Android Chrome as of 2022-10-20 -, a basic web worker is used. In this case it is not cross-tab safe.

Status

This is still experimental:

  • slow
  • not fully tested
  • bugs
  • Wasm support issue: Currently deleteDatabase is not supported on wasm (investigating)

Libraries

setup
sqflite_ffi_web