SQLite डेटाबेस एकीकरण

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

// NOTE: getDatabasesPath() requires Flutter context.
// This main method is for demonstration.
// In a real Flutter app, _initDatabase would be called
// from a StatefulWidget or similar.

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

  factory DatabaseHelper() {
    return _instance;
  }

  DatabaseHelper._internal();

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

  Future<Database> _initDatabase() async {
    // Get the default databases location for the platform
    String path = await getDatabasesPath();
    String dbPath = join(path, 'item_database.db');

    return await openDatabase(
      dbPath,
      version: 1,
      onCreate: (db, version) {
        // Table creation logic will go here
        print('Database created or opened.');
      },
    );
  }
}

void main() async {
  // This main is illustrative. sqflite operations need a
  // running Flutter app context to fully function (e.g. for getDatabasesPath).
  // When run in a Flutter app, DatabaseHelper().database
  // would ensure the DB is initialized.
  print('DatabaseHelper class defined.');
}

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

class DatabaseHelper {
  static final DatabaseHelper _instance = DatabaseHelper._internal();
  static Database? _database;
  factory DatabaseHelper() { return _instance; }
  DatabaseHelper._internal();
  Future<Database> get database async { if (_database != null) return _database!; _database = await _initDatabase(); return _database!; }
  Future<Database> _initDatabase() async {
    String path = await getDatabasesPath();
    String dbPath = join(path, 'item_database.db');
    return await openDatabase(dbPath, version: 1,
      onCreate: (db, version) async {
        // SQL to create the items table
        await db.execute(
          '''
          CREATE TABLE items(
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            name TEXT,
            quantity INTEGER
          )
          '''
        );
        print('Table "items" created successfully.');
      },
    );
  }
}

void main() async {
  // This main is illustrative. In a Flutter app,
  // calling DatabaseHelper().database would trigger
  // _initDatabase and the onCreate callback.
  print('Database helper configured for table creation.');
}

class Item {
  final int? id;
  final String name;
  final int quantity;

  Item({this.id, required this.name, required this.quantity});

  // Convert an Item into a Map. Keys must match DB column names.
  Map<String, dynamic> toMap() {
    return {
      'id': id,
      'name': name,
      'quantity': quantity,
    };
  }

  // Create an Item object from a Map (database row).
  static Item fromMap(Map<String, dynamic> map) {
    return Item(
      id: map['id'],
      name: map['name'],
      quantity: map['quantity'],
    );
  }

  @override
  String toString() {
    return 'Item(id: $id, name: $name, quantity: $quantity)';
  }
}

void main() {
  final myItem = Item(id: 1, name: 'Apple', quantity: 5);
  print('Created Item: ${myItem.toString()}');
  print('Converted to Map: ${myItem.toMap()}');

  final itemMap = {'id': 2, 'name': 'Banana', 'quantity': 3};
  final itemFromMap = Item.fromMap(itemMap);
  print('Item from Map: ${itemFromMap.toString()}');
}

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

// Item class (from previous scene, for self-containment)
class Item {
  final int? id; final String name; final int quantity;
  Item({this.id, required this.name, required this.quantity});
  Map<String, dynamic> toMap() { return {'id': id, 'name': name, 'quantity': quantity}; }
  static Item fromMap(Map<String, dynamic> map) { return Item(id: map['id'], name: map['name'], quantity: map['quantity']); }
  @override
  String toString() { return 'Item(id: $id, name: $name, quantity: $quantity)'; }
}

class DatabaseHelper {
  static final DatabaseHelper _instance = DatabaseHelper._internal();
  static Database? _database;
  factory DatabaseHelper() { return _instance; }
  DatabaseHelper._internal();
  Future<Database> get database async { if (_database != null) return _database!; _database = await _initDatabase(); return _database!; }
  Future<Database> _initDatabase() async {
    String path = await getDatabasesPath();
    String dbPath = join(path, 'item_database.db');
    return await openDatabase(dbPath, version: 1,
      onCreate: (db, version) async {
        await db.execute('''
          CREATE TABLE items(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, quantity INTEGER)
          ''');
      },
    );
  }

  Future<int> insertItem(Item item) async {
    final db = await database;
    return await db.insert(
      'items',
      item.toMap(),
      conflictAlgorithm: ConflictAlgorithm.replace, // Replace if ID exists
    );
  }
}

void main() async {
  // Illustrative main. In a Flutter app, you'd call:
  // final dbHelper = DatabaseHelper();
  // final newItem = Item(name: 'Milk', quantity: 2);
  // int id = await dbHelper.insertItem(newItem);
  // print('Inserted item with id: $id');
  print('Item insertion logic defined in DatabaseHelper.');
}

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

// Item class (for self-containment)
class Item {
  final int? id; final String name; final int quantity;
  Item({this.id, required this.name, required this.quantity});
  Map<String, dynamic> toMap() { return {'id': id, 'name': name, 'quantity': quantity}; }
  static Item fromMap(Map<String, dynamic> map) { return Item(id: map['id'], name: map['name'], quantity: map['quantity']); }
  @override
  String toString() { return 'Item(id: $id, name: $name, quantity: $quantity)'; }
}

class DatabaseHelper {
  static final DatabaseHelper _instance = DatabaseHelper._internal();
  static Database? _database;
  factory DatabaseHelper() { return _instance; }
  DatabaseHelper._internal();
  Future<Database> get database async { if (_database != null) return _database!; _database = await _initDatabase(); return _database!; }
  Future<Database> _initDatabase() async {
    String path = await getDatabasesPath();
    String dbPath = join(path, 'item_database.db');
    return await openDatabase(dbPath, version: 1,
      onCreate: (db, version) async {
        await db.execute('''
          CREATE TABLE items(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, quantity INTEGER)
          ''');
      },
    );
  }

  Future<List<Item>> getItems() async {
    final db = await database;
    // Query all the items from the table
    final List<Map<String, dynamic>> maps = await db.query('items');

    // Convert the List<Map<String, dynamic>> into a List<Item>.
    return List.generate(maps.length, (i) {
      return Item.fromMap(maps[i]);
    });
  }
}

void main() async {
  // Illustrative main. In a Flutter app, you'd call:
  // final dbHelper = DatabaseHelper();
  // await dbHelper.insertItem(Item(name: 'Bread', quantity: 1));
  // final items = await dbHelper.getItems();
  // print('Retrieved items: $items');
  print('Item query logic defined in DatabaseHelper.');
}

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

// Item class (for self-containment)
class Item {
  final int? id; final String name; final int quantity;
  Item({this.id, required this.name, required this.quantity});
  Map<String, dynamic> toMap() { return {'id': id, 'name': name, 'quantity': quantity}; }
  static Item fromMap(Map<String, dynamic> map) { return Item(id: map['id'], name: map['name'], quantity: map['quantity']); }
  @override
  String toString() { return 'Item(id: $id, name: $name, quantity: $quantity)'; }
}

class DatabaseHelper {
  static final DatabaseHelper _instance = DatabaseHelper._internal();
  static Database? _database;
  factory DatabaseHelper() { return _instance; }
  DatabaseHelper._internal();
  Future<Database> get database async { if (_database != null) return _database!; _database = await _initDatabase(); return _database!; }
  Future<Database> _initDatabase() async {
    String path = await getDatabasesPath();
    String dbPath = join(path, 'item_database.db');
    return await openDatabase(dbPath, version: 1,
      onCreate: (db, version) async {
        await db.execute('''
          CREATE TABLE items(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, quantity INTEGER)
          ''');
      },
    );
  }

  Future<int> updateItem(Item item) async {
    final db = await database;
    return await db.update(
      'items',
      item.toMap(),
      where: 'id = ?', // Specify which item to update
      whereArgs: [item.id],
    );
  }
}

void main() async {
  // Illustrative main. In a Flutter app, you'd call:
  // final dbHelper = DatabaseHelper();
  // // Assume item with id 1 exists
  // var updatedItem = Item(id: 1, name: 'Milk', quantity: 3);
  // int count = await dbHelper.updateItem(updatedItem);
  // print('Updated $count item(s).');
  print('Item update logic defined in DatabaseHelper.');
}

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

// Item class (for self-containment)
class Item {
  final int? id; final String name; final int quantity;
  Item({this.id, required this.name, required this.quantity});
  Map<String, dynamic> toMap() { return {'id': id, 'name': name, 'quantity': quantity}; }
  static Item fromMap(Map<String, dynamic> map) { return Item(id: map['id'], name: map['name'], quantity: map['quantity']); }
  @override
  String toString() { return 'Item(id: $id, name: $name, quantity: $quantity)'; }
}

class DatabaseHelper {
  static final DatabaseHelper _instance = DatabaseHelper._internal();
  static Database? _database;
  factory DatabaseHelper() { return _instance; }
  DatabaseHelper._internal();
  Future<Database> get database async { if (_database != null) return _database!; _database = await _initDatabase(); return _database!; }
  Future<Database> _initDatabase() async {
    String path = await getDatabasesPath();
    String dbPath = join(path, 'item_database.db');
    return await openDatabase(dbPath, version: 1,
      onCreate: (db, version) async {
        await db.execute('''
          CREATE TABLE items(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, quantity INTEGER)
          ''');
      },
    );
  }

  Future<int> deleteItem(int id) async {
    final db = await database;
    return await db.delete(
      'items',
      where: 'id = ?',
      whereArgs: [id],
    );
  }
}

void main() async {
  // Illustrative main. In a Flutter app, you'd call:
  // final dbHelper = DatabaseHelper();
  // // Assume item with id 1 exists
  // int count = await dbHelper.deleteItem(1);
  // print('Deleted $count item(s).');
  print('Item deletion logic defined in DatabaseHelper.');
}