drift/moor_ffi

moor_ffi

Dart bindings to sqlite by using dart:ffi. This library contains utils to make integration with moor easier, but it can also be used as a standalone package. It also doesn't depend on Flutter, so it can be used on Dart VM applications as well.

Supported platforms

You can make this library work on any platform that lets you obtain a DynamicLibrary in which sqlite's symbols are available (see below).

Out of the box, this library supports all platforms where sqlite3 is installed:

• iOS: Yes
• macOS: Yes
• Linux: Available on most distros
• Windows: Additional setup is required
• Android: Yes when used with Flutter

Unless explicitly noted, this library works with and without Flutter. If you're using Flutter, this library will bundle sqlite3 in your Android app. This requires the Android NDK to be installed (You can get the NDK in the SDK Manager of Android Studio). Note that the first flutter run is going to take a very long time as we need to compile sqlite.

On other platforms

Using this library on platforms that are not supported out of the box is fairly straightforward. For instance, if you release your own sqlite3.so next to your application, you could use

import 'dart:ffi';
import 'dart:io';
import 'package:moor_ffi/database.dart';
import 'package:moor_ffi/open_helper.dart';

void main() {
  open.overrideFor(OperatingSystem.linux, _openOnLinux);

  final db = Database.memory();
  db.close();
}

DynamicLibrary _openOnLinux() {
  final script = File(Platform.script.toFilePath());
  final libraryNextToScript = File('${script.path}/sqlite3.so');
  return DynamicLibrary.open(libraryNextToScript.path);
}

Just be sure to first override the behavior and then open the database. Further, if you want to use the isolate api, you can only use a static method or a top-level function to open the library. For Windows, a similar setup with a sqlite3.dll library should work.

Supported datatypes

This library supports null, int, double, String and Uint8List to bind args. Returned columns from select statements will have the same types.

Using without moor

import 'package:moor_ffi/database.dart';

void main() {
  final database = Database.memory();
  // run some database operations. See the example for details
  database.close();
}

Be sure to always call Database.close to avoid memory leaks!

Using with moor

If you're migrating an existing project using moor_flutter, see the documentation.

Add both moor and moor_ffi to your pubspec:

dependencies:
  moor: ^2.0.0
  moor_ffi: ^0.2.0
dev_dependencies:
  moor_generator: ^2.0.0

You can then use a VmDatabase as an executor:

@UseMoor(...)
class MyDatabase extends _$MyDatabase {

  MyDatabase(): super(VmDatabase(File('app.db')));
}

If you need to find an appropriate directory for the database file, you can use the LazyDatabase wrapper from moor. It can be used to create the inner VmDatabase asynchronously:

import 'package:path_provider/path_provider.dart';
import 'package:path/path.dart' as p;

// use this instead of VmDatabase(...)
LazyDatabase(() async {
  final dbFolder = await getApplicationDocumentsDirectory();
  final file = File(p.join(dbFolder.path, 'app.db'));
  return VmDatabase(file);
});