https://pub.dev/packages/floor
Konfigurieren Sie die Referenz pubspec.yaml der abhängigen Bibliothek im Flutter-Projekt
dependencies:
flutter:
sdk: flutter
floor: ^1.2.0
dev_dependencies:
floor_generator: ^1.2.0
build_runner: ^2.1.2
Entität erstellen und [project_root]/lib/app/data/entity/vegetalbe.dart anzeigen
import 'package:floor/floor.dart';
@Entity(tableName: "vegetables")
class Vegetable {
@PrimaryKey(autoGenerate: true)
final int? id;
final String name;
final String locale;
final String desc;
@ColumnInfo(name: 'created_at')
final int createTime;
@ColumnInfo(name: 'updated_at')
final int updateTime;
Vegetable(
this.id,
this.name,
this.locale,
this.desc, {
int? createTime,
int? updateTime,
}) : this.createTime = createTime ?? DateTime.now().millisecondsSinceEpoch,
this.updateTime = updateTime ?? DateTime.now().millisecondsSinceEpoch;
}
@DatabaseView(
'SELECT v.id, v.name, v.desc, v.locale, uf.hash, uf.ext, v.created_at, v.updated_at from vegetables v LEFT OUTER JOIN upload_file_morph ufm on v.id = ufm.related_id LEFT OUTER JOIN upload_file uf on ufm.upload_file_id = uf.id;',
viewName: "vegetables_v")
class VegetableV {
final int id;
final String name;
final String locale;
final String? desc;
final String? hash;
final String? ext;
@ColumnInfo(name: 'created_at')
final int createTime;
@ColumnInfo(name: 'updated_at')
final int updateTime;
VegetableV(
this.id,
this.name,
this.locale,
this.desc,
this.hash,
this.ext, {
int? createTime,
int? updateTime,
}) : this.createTime = createTime ?? DateTime.now().millisecondsSinceEpoch,
this.updateTime = updateTime ?? DateTime.now().millisecondsSinceEpoch;
}
Spezifische Details finden Sie unter https://floor.codes/database-views/
Erstellen Sie "Datenzugriffsobjekte" gemäß der Ansicht[project_root]/lib/app/data/dao/vegetalbe_dao.dart
import 'package:floor/floor.dart';
import 'package:strapi_flutter_internation_poc/app/data/entity/vegetable.dart';
@dao
abstract class VegetableDao {
@Query('SELECT * FROM vegetables_v')
Future<List<VegetableV>> findAll();
}
Erstellen Sie die Datenbankverwaltungsklasse [project_root]/lib/app/data/database.dart
import 'dart:async';
import 'package:floor/floor.dart';
import 'package:sqflite/sqflite.dart' as sqflite;
// daos
import 'dao/vegetable_dao.dart';
// entitys
import 'entity/vegetable.dart';
part 'database.g.dart'; // the generated code will be there
@Database(version: 1, entities: [Vegetable], views: [VegetableV])
abstract class AppDatabase extends FloorDatabase {
VegetableDao get vegetableDao;
}
Führen Sie den Codegenerator von Floor aus
flutter packages pub run build_runner build
[INFO] Generating build script...
[INFO] Generating build script completed, took 480ms
[INFO] Initializing inputs
[INFO] Reading cached asset graph...
[INFO] Reading cached asset graph completed, took 67ms
[INFO] Checking for updates since last build...
[INFO] Checking for updates since last build completed, took 651ms
[INFO] Running build...
[INFO] 1.1s elapsed, 0/1 actions completed.
[INFO] 2.2s elapsed, 0/1 actions completed.
[INFO] 4.0s elapsed, 0/1 actions completed.
[INFO] 8.4s elapsed, 0/1 actions completed.
[INFO] Running build completed, took 8.8s
[INFO] Caching finalized dependency graph...
[INFO] Caching finalized dependency graph completed, took 34ms
[INFO] Succeeded after 8.8s with 2 outputs (2 actions)
Dadurch wird ein database.g.dart generiert im selben Verzeichnis wie database.dart
Verwenden Sie das Dienstschema von GetX, um den DB-Dienst [project_root]/lib/app/common/services/db_service.dart.dart zu erstellen
Bitte beachten Sie hier besonders
Im Gegensatz zur offiziellen Dokumentation von Floor generiert Floor eine SQLite-Datenbank basierend auf der Entität. Ich werde Floor die vorhandenen Datenbankdateien zur Verwendung zur Verfügung stellen, ohne neue Datenbankdateien zu generieren.
import 'dart:io';
import 'package:get/get.dart';
import 'package:path/path.dart';
import 'package:floor/floor.dart';
import 'package:flutter/services.dart';
import 'package:sqflite/sqflite.dart';
import 'package:strapi_flutter_internation_poc/app/data/database.dart';
class DbService extends GetxService {
static DbService get to => Get.find();
late AppDatabase db;
Future<DbService> init() async {
final callback = Callback(
onCreate: (database, version) {},
onOpen: (database) {
print('onOpen database');
getDatabasesPath().then((value) => print(value));
},
onUpgrade: (database, startVersion, endVersion) {},
);
var dbDir = await getDatabasesPath();
var dbPath = join(dbDir, "app_database.db");
await deleteDatabase(dbPath);
ByteData data = await rootBundle.load("assets/db/data.db");
List<int> bytes =
data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes);
await File(dbPath).writeAsBytes(bytes);
db = await $FloorAppDatabase
.databaseBuilder(dbPath)
.addCallback(callback)
.build();
return this;
}
}
Instanziieren Sie DbService [project_root]/lib/main.dart
Future<void> main() async {
WidgetsFlutterBinding.ensureInitialized();
await initServices();
runApp(
GetMaterialApp(
title: "Application",
initialRoute: AppPages.INITIAL,
getPages: AppPages.routes,
),
);
}
Future<void> initServices() async {
print('starting services ...');
await Get.putAsync(() => DbService().init());
print('All services started...');
}
Ändern Sie den home_controller-Code, um die Sqlite-Datenbank [project_root]/lib/app/modules/home/controllers/home_controller.dart zu lesen
import 'package:get/get.dart';
import 'package:strapi_flutter_internation_poc/app/common/services/db_service.dart';
import 'package:strapi_flutter_internation_poc/app/data/entity/vegetable.dart';
class HomeController extends GetxController {
final vegetables = Rx<List<VegetableV>>([]);
@override
void onInit() {
super.onInit();
}
@override
void onReady() {
super.onReady();
}
Future<void> getAllVegetables() async {
final result = await DbService.to.db.vegetableDao.findAll();
vegetables.value = result;
}
@override
void onClose() {}
}
Teste es kurz
controller.getAllVegetables();
Future<void> getAllVegetables() async {
final result = await DbService.to.db.vegetableDao.findAll();
vegetables.value = result;
print(result);
}
aus
I/flutter ( 7396): starting services ...
I/flutter ( 7396): onOpen database
I/flutter ( 7396): /data/user/0/com.nasawz.strapi_flutter_internation_poc.strapi_flutter_internation_poc/databases
I/flutter ( 7396): All services started...
[GETX] Instance "DbService" has been created
[GETX] Instance "DbService" has been initialized
[GETX] Instance "GetMaterialController" has been created
[GETX] Instance "GetMaterialController" has been initialized
[GETX] GOING TO ROUTE /home
[GETX] Instance "HomeController" has been created
[GETX] Instance "HomeController" has been initialized
I/flutter ( 7396): [Instance of 'VegetableV', Instance of 'VegetableV', Instance of 'VegetableV', Instance of 'VegetableV', Instance of 'VegetableV', Instance of 'VegetableV', Instance of 'VegetableV', Instance of 'VegetableV']
Erfolg! Die Daten werden ausgelesen.
Verwenden Sie die Obx-Funktion von GetX, um Daten auf der Benutzeroberfläche anzuzeigen
import 'package:flutter/material.dart';
import 'package:get/get.dart';
import '../controllers/home_controller.dart';
class HomeView extends GetView<HomeController> {
@override
Widget build(BuildContext context) {
controller.getAllVegetables();
return Scaffold(
appBar: AppBar(
title: Text('Vegetables'),
centerTitle: true,
),
body: Obx(() => ListView.builder(
itemCount: controller.vegetables.value.length,
itemBuilder: (context, index) {
var vegetable = controller.vegetables.value[index];
return Padding(
padding: const EdgeInsets.all(18.0),
child: Container(
child: Row(
children: [
Container(
// color: Colors.red,
child: Image.asset(
'strapi/public/uploads/thumbnail_${vegetable.hash}${vegetable.ext}',
fit: BoxFit.contain,
width: 140,
height: 140,
),
),
Container(
width: Get.width - 18 * 2 - 140 - 18,
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(
vegetable.name,
style: Get.textTheme.headline6,
),
Text(
vegetable.desc!,
style: Get.textTheme.subtitle1,
maxLines: 1,
overflow: TextOverflow.ellipsis,
),
],
),
),
],
),
),
);
})),
);
}
}
