pubspec.yaml

Add drift database plugin to your project check the official page for latest version updates.

dependencies:
  flutter:
    sdk: flutter

  cupertino_icons: ^1.0.8
  drift: ^2.28.1
  path_provider: ^2.1.5
  path: ^1.9.1

users.dart

Create a users table where we have fields id, name and age.

import 'package:drift/drift.dart';

class Users extends Table {
  IntColumn get id => integer().autoIncrement()();
  TextColumn get name => text().withLength(min: 3, max: 50)();
  IntColumn get age => integer().nullable()();
}

app_database.dart

Creating a database file where we customize the drift database with the required CRUD operations.

import 'dart:io';

import 'package:drift/drift.dart';
import 'package:drift/native.dart';
import 'package:path_provider/path_provider.dart';
import 'users.dart';
import 'package:path/path.dart' as p;
part 'app_database.g.dart';


@DriftDatabase(tables: [Users])
class AppDatabase extends _$AppDatabase {
  AppDatabase() : super(_openConnection());

  @override
  int get schemaVersion => 1;

  Future<int> insertUser(UsersCompanion user) {
    return into(users).insert(user);
  }

  Future<List<User>> getAllUsers(){
    return select(users).get();
  }

  Future<bool> updateUser(User user) => update(users).replace(user);

  Future<int> deleteUser(int id){
    return (delete(users)..where((tbl)=> tbl.id.equals(id))).go();
  }

  Future<List<User>> getUsersAboveAge(){
    return (select(users)..where((u) => u.age.isBiggerThanValue(27))).get();
  }

  Future<List<User>> getUserOrderByAge(){
    return (select(users)..orderBy([(u) => OrderingTerm(expression: u.age, mode: OrderingMode.desc)])).get();
  }
}


LazyDatabase _openConnection() {
  return LazyDatabase(() async {
    final dbFolder = await getApplicationDocumentsDirectory();
    final file = File(p.join(dbFolder.path, 'app.db'));
    return NativeDatabase(file);
  });
}

Now we have to generate app_database.g.dart using the below command running through terminal. may refer video tutorial there i have clearly explained generating the file.

flutter pub run build_runner build

userpage.dart

In this page we have a designed a simple user interface to insert, delete & update the user information.

import 'package:drift/drift.dart' as d;
import 'package:flutter_drift/main.dart';
import 'package:flutter/material.dart';

import 'app_database.dart';

class UserPage extends StatefulWidget {
  final User user;
  const UserPage({super.key, required this.user});

  @override
  State<UserPage> createState() => _UserPageState();
}

class _UserPageState extends State<UserPage> {
  final db = database;
  late TextEditingController _nameController;
  late TextEditingController _ageController;

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    _nameController = TextEditingController(text: widget.user.name);
    _ageController = TextEditingController(text: widget.user.age.toString());
  }

  Future<void> _updateuser() async {
    final updatedUser = widget.user.copyWith(
      name: _nameController.text,
      age: d.Value(int.tryParse(_ageController.text)),
    );
    await db.updateUser(updatedUser);

    await Navigator.push(context, MaterialPageRoute(builder: (_) => MyApp()));
  }

  Future<void> _deleteUser() async {
    await db.deleteUser(widget.user.id);
    await Navigator.push(context, MaterialPageRoute(builder: (_) => MyApp()));
  }

  Future<void> _addUser() async {
    await db.insertUser(UsersCompanion.insert(name: _nameController.text, age: d.Value(int.tryParse(_ageController.text))));
    await Navigator.push(context, MaterialPageRoute(builder: (_) => MyApp()));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text("User details"),),
      body: Padding(
          padding: const EdgeInsets.all(16),
      child: Column(
        children: [
          TextField(
            controller: _nameController,
            decoration: const InputDecoration(labelText: "Name"),
          ),
          const SizedBox(height: 10),
          TextField(
            controller: _ageController,
            decoration: const InputDecoration(labelText: "Age"),
          ),
          const SizedBox(height: 20),
          Row(
            children: [
              ElevatedButton(onPressed: _updateuser, child: const Text("Update")),
              const SizedBox(height: 20),
              ElevatedButton(onPressed: _deleteUser, child: const Text("Delete")),
              const SizedBox(height: 20),
              ElevatedButton(onPressed: _addUser, child: const Text("Add"))
            ],
          )
        ],
      ),
      ),
    );
  }
}

Creating Database Views

import 'package:drift/drift.dart';

part 'app_database.g.dart';

class Products extends Table {

  IntColumn get id =>  integer().autoIncrement()();
  TextColumn get title => text()();
  TextColumn get description => text()();
}

abstract class ProductsView extends View{
  Products get products;

  @override
  Query as() => select([
    products.title
  ]).from(products);
}

@DriftDatabase(tables:[
  Products
], views:[
  ProductsView
])

class Database extends _$Database {
  Database(QueryExecutor e): super(e);

  @override
  int get schemaVersion => 2;
}

main.dart

In the main.dart file we try loading the list view so that we can display the user information.

import 'package:drift/drift.dart' as d;
import 'package:flutter/material.dart';
import 'package:flutter_drift/database/app_database.dart';

import 'database/userpage.dart';

late AppDatabase database;

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  database = AppDatabase();

  runApp(MyApp());
}

class MyApp extends StatefulWidget {

  const MyApp({super.key});

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  late Future<List<User>> _usersList;

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    setState(() {
      _usersList = database.getAllUsers();
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Drift CRUD Example',
      home: Scaffold(
        appBar: AppBar(title: Text("Home")),
        body: Column(
          children: [
            TextButton(onPressed: (){
              setState(() {
                _usersList = database.getUsersAboveAge();
              });
            }, child: Text("Filter")),
            TextButton(onPressed: (){
              setState(() {
                _usersList = database.getUserOrderByAge();
              });
            }, child: Text("Order By")),
           Expanded(child:  displayListView(),)
          ],
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () async {
            database.insertUser(UsersCompanion.insert(
                name: "Abhi",
            age: d.Value(25)));
            setState(() {});
          },
          child: Text("+"),
        ),
      ),
    );
  }

  FutureBuilder<List<User>> displayListView() {
    return FutureBuilder(
        future: _usersList,
        builder: (context, snapshot) {
          if (!snapshot.hasData) {
            return Center(child: CircularProgressIndicator());
          }
          final users = snapshot.data;

          return ListView.builder(
            itemCount: users?.length,
            itemBuilder: (context, index) {
              return ListTile(
                  title: Text(users![index].name),
                subtitle: Text(users[index].age.toString()),
                onTap: () async {
                    await Navigator.push(context,
                    MaterialPageRoute(builder: (_) => UserPage(user: users[index],)));
                },
              );
            },
          );
        },
      );
  }
}