Getting Started
Being built on top of the sqlite3 database, drift can run on almost every Dart platform. Since the initial release, the Dart and Flutter ecosystems have changed a lot. To clear confusion about different drift packages and when to use them, this document lists all supported platforms and how to use drift when building apps for them.
To achieve platform independence, drift separates its core apis from a platform-specific
database implementation. The core apis are pure-Dart and run on all Dart platforms, even
outside of Flutter. When writing drift apps, prefer to mainly use the apis in
package:drift/drift.dart
as they are guaranteed to work across all platforms.
Depending on your platform, you can choose a different QueryExecutor
- the interface
binding the core drift library with native databases.
Overview¶
This table list all supported drift implementations and on which platforms they run on.
Implementation | Supported platforms | Notes |
---|---|---|
SqfliteQueryExecutor from package:drift_sqflite |
Android, iOS | Uses platform channels, Flutter only, no isolate support, doesn't support flutter test . Formerly known as moor_flutter |
NativeDatabase from package:drift/native.dart |
Android, iOS, Windows, Linux, macOS | No further setup is required for Flutter users. For support outside of Flutter, or in flutter test , see the desktop section below. Usage in a isolate is recommended. Formerly known as package:moor/ffi.dart . |
WasmDatabase from package:drift/wasm.dart |
Web | Works with or without Flutter. A bit of additional setup is required. |
WebDatabase from package:drift/web.dart |
Web | Deprecated in favor of WasmDatabase . |
To support all platforms in a shared codebase, you only need to change how you open your database, all other usages can stay the same. This repository gives an example on how to do that with conditional imports.
Mobile (Android and iOS)¶
There are two drift implementations for mobile that you can use:
using drift_sqflite
¶
drift_sqflite
(formerly known as moor_flutter
) is a package using the sqflite
package to
provide a drift database implementation.
They use Flutter's package channels and support both Android and iOS. They don't work in Dart
projects not using flutter.
For new projects, we generally recommend the newer ffi-based implementation, but drift_sqflite
is maintaned and supported too.
using drift/native
¶
The new package:drift/native.dart
implementation uses dart:ffi
to bind to sqlite3's native C apis.
This is the recommended approach for newer projects as described in the getting started guide.
To ensure that your app ships with the latest sqlite3 version, also add a dependency to the sqlite3_flutter_libs
package when using package:drift/native.dart
!
sqlite3_flutter_libs
will configure your app to use a fixed sqlite3 version on Android, iOS and macOS.
It only applies to your full Flutter app though, it can't override the sqlite3 version when running tests
with flutter test
.
A note on ffi and Android
package:drift/native.dart
is the recommended drift implementation for new Android apps.
However, there are some smaller issues on some devices that you should be aware of:
- Using
sqlite3_flutter_libs
will include prebuilt binaries for 32-bitx86
devices which you probably won't need. You can apply a filter in yourbuild.gradle
to remove those binaries. - Opening
libsqlite3.so
fails on some Android 6.0.1 devices. This can be fixed by settingandroid.bundle.enableUncompressedNativeLibs=false
in yourgradle.properties
file. Note that this will increase the disk usage of your app. See this issue for details. - Out of memory errors for very complex queries: Since the regular tmp directory isn't available on Android, you need to inform sqlite3 about the right directory to store temporary data. See this comment for an example on how to do that.
Web¶
Main article: Web
Drift runs on the web by compiling sqlite3 to a WebAssembly module. This database
can be accessed using a WasmDatabase
in package:drift/wasm.dart
.
For optimal support across different browsers, a worker script and some additional
setup is required. The main article explains how to set up drift to work on the web.
Desktop¶
Drift also supports all major Desktop operating systems where Dart runs on by using the
NativeDatabase
from package:drift/native.dart
. Depending on your operating system, further
setup might be required:
Windows¶
For Flutter apps, depending on the sqlite3_flutter_libs
package is enough. It will automatically
bundle the latest sqlite3 version with your app as a DLL, and drift will automatically use that
version.
If you don't want to use sqlite3_flutter_libs
, or if you're not running as a Flutter app
(keep in mind that flutter test
does not run as a full Flutter app!), you can download sqlite
and extractsqlite3.dll
into a folder that's in your PATH
environment variable to use drift.
You can also ship a custom sqlite3.dll
along with your app. See the section below for
details.
Linux¶
When depending on sqlite3_flutter_libs
in your pubspec and using Flutter, no additional setup
is necessary.
When not running as a Flutter app (this includes flutter test
!), you need to either use a
sqlite3
build from your distribution or include a custom libsqlite3.so
.
On most distributions, libsqlite3.so
is installed already. If you only need to use drift for
development, you can just install the sqlite3 libraries. On Ubuntu and other Debian-based
distros, you can install the libsqlite3-dev
package for this. Virtually every other distribution
will also have a prebuilt package for sqlite.
You can also ship a custom libsqlite3.so
along with your app. See the section below for
details.
macOS¶
This one is easy! Just use the NativeDatabase
from package:drift/native.dart
. No further setup is
necessary.
If you need a custom sqlite3 library, or want to make sure that your app will always use a
specific sqlite3 version, you can also ship that version with your app.
When depending on sqlite3_flutter_libs
, drift will automatically use that version which is
usually more recent than the sqlite3
version that comes with macOS.
Again, note that this only works with full Flutter apps and not in say flutter test
.
For tests or using a custom sqlite3 version without sqlite3_flutter_libs
, see the following
section.
Bundling sqlite with your app¶
If you don't want to use the sqlite3
version from the operating system (or if it's not
available), you can also ship sqlite3
with your app.
The best way to do that depends on how you ship your app. Here, we assume that you can
install the dynamic library for sqlite
next to your application executable.
This example shows how to do that on Linux, by using a custom sqlite3.so
that we assume
lives next to your application:
import 'dart:ffi';
import 'dart:io';
import 'package:sqlite3/open.dart';
void main() {
open.overrideFor(OperatingSystem.linux, _openOnLinux);
// After setting all the overrides, you can use drift!
}
DynamicLibrary _openOnLinux() {
final scriptDir = File(Platform.script.toFilePath()).parent;
final libraryNextToScript = File('${scriptDir.path}/sqlite3.so');
return DynamicLibrary.open(libraryNextToScript.path);
}
// _openOnWindows could be implemented similarly by opening `sqlite3.dll`
Be sure to use drift after you set the platform-specific overrides. When you use drift in another isolate, you'll also need to apply the opening overrides on that background isolate. You can call them in the isolate's entrypoint before using any drift apis.
For standard Flutter tests running in a Dart VM without native plugins, you can use a
flutter_test_config.dart
file to ensure that a recent version of sqlite3 is available.
An example for this is available here.
For Dart tests, a similar logic could be put into a setupAll
callback.