moor_ffi

Experimental 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.

Warnings

At the moment, dart:ffi is in preview and there will be breaking changes that this library has to adapt to. This library has been tested on Dart 2.5.0. If you're using a development Dart version (this can include any Flutter channels that are not stable), this library might not work.

Also, please don't use this library on production apps yet.

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

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();
}

You can also use an asynchronous API on a background isolate by using IsolateDb.openFile or IsolateDb.openMemory, respectively. Be aware that the asynchronous API is much slower, but it moves work out of the UI isolate.

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

Using with moor

Add both moor and moor_ffi to your pubspec, the moor_flutter dependency can be dropped.

dependencies:
  moor: ^1.7.0
  moor_ffi: ^0.0.1
dev_dependencies:
  moor_generator: ^1.7.0

In the file where you created a FlutterQueryExecutor, replace the moor_flutter import with both package:moor/moor.dart and package:moor_ffi/moor_ffi.dart. In all other project files that use moor apis (e.g. a Value class for companions), just import package:moor/moor.dart.

Finally, replace usages of FlutterQueryExecutor with VmDatabase.

Note that, at the moment, there is no direct counterpart for FlutterQueryExecutor.inDatabasePath and that the async API using a background isolate is not available for moor yet.

Libraries

database
Exports the low-level Database and IsolateDb classes to run operations on a sqflite database.
moor_ffi
open_helper
Utils to open a DynamicLibrary on platforms that aren't supported by moor_ffi by default.