在颤动中获取SQFLITE数据库的数据

dependencies:
  sqflite: ^1.3.2+2
  path_provider: ^2.0.5

import 'package:sqflite/sqflite.dart';
import 'package:path/path.dart';
import 'package:path_provider/path_provider.dart';

class User {
  final int id;
  final String name;

  User({required this.id, required this.name});
}

class DatabaseProvider {
  static final DatabaseProvider _instance = DatabaseProvider._internal();
  static Database? _database;

  factory DatabaseProvider() {
    return _instance;
  }

  DatabaseProvider._internal();

  Future<Database> get database async {
    if (_database != null) {
      return _database!;
    }
    _database = await createDatabase();
    return _database!;
  }

  Future<Database> createDatabase() async {
    final documentsDirectory = await getApplicationDocumentsDirectory();
    final path = join(documentsDirectory.path, 'my_database.db');
    return await openDatabase(
      path,
      version: 1,
      onCreate: (Database db, int version) async {
        await db.execute('''
          CREATE TABLE users(
            id INTEGER PRIMARY KEY,
            name TEXT
          )
        ''');
      },
    );
  }

  Future<List<User>> getUsers() async {
    final db = await database;
    final List<Map<String, dynamic>> maps = await db.query('users');
    return List.generate(maps.length, (i) {
      return User(
        id: maps[i]['id'],
        name: maps[i]['name'],
      );
    });
  }
}

final user = User(id: 1, name: 'John');
final dbProvider = DatabaseProvider();
final db = await dbProvider.database;
await db.insert('users', user.toMap(), conflictAlgorithm: ConflictAlgorithm.replace);

final dbProvider = DatabaseProvider();
final users = await dbProvider.getUsers();
users.forEach((user) {
  print('User: ${user.name}');
});