import 'package:flutter/material.dart'; import 'package:sqflite/sqflite.dart'; import 'db_helper.dart'; import 'customer.dart'; class CustomerProvider with ChangeNotifier { List _customers = []; List get customers => _customers; Future fetchCustomers() async { final db = await DbHelper().database; final List> maps = await db.query('customers'); _customers = List.generate(maps.length, (i) { return Customer.fromMap(maps[i]); }); notifyListeners(); } Future addCustomer(Customer customer) async { final db = await DbHelper().database; await db.insert('customers', customer.toMap()); fetchCustomers(); } // 追加の CRUD メソッドを実装 }