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Get Started with Sequelize Dart

Welcome to Sequelize Dart! This guide will help you get started with using Sequelize Dart in your Dart projects.

Prerequisites​

Sequelize Dart uses a Node.js bridge to communicate with the Sequelize.js runtime. You must have Node.js installed before using this package.

Install Node.js​

Download and install Node.js v18 or later from nodejs.org.

Alternatively, use a version manager:

# Install with nvm
nvm install 18
nvm use 18

# Or install with fnm
fnm install 18
fnm use 18

Verify your installation:

node --version
# Should print v18.x.x or later
warning

Sequelize Dart will not work without Node.js. The ORM uses a background Node.js process to run Sequelize.js queries against your database.

Installation​

Add Sequelize Dart to your pubspec.yaml:

dependencies:
  sequelize_orm: ^0.2.0

dev_dependencies:
  sequelize_orm_generator: ^0.2.0
  build_runner: ^2.4.0

Then run:

dart pub get

Database Connection​

Sequelize Dart supports PostgreSQL, MySQL, MariaDB, SQLite. Here's how to set up a connection:

import 'package:sequelize_orm/sequelize_orm.dart';

void main() async {
  // Create Sequelize instance with PostgreSQL connection
  final sequelize = Sequelize().createInstance(
    connection: SequelizeConnection.postgres(
      url: 'postgresql://username:password@localhost:5432/database_name',
    ),
    logging: (sql) => SqlFormatter.printFormatted(sql),
  );

  // Initialize with your models
  await sequelize.initialize(
    models: [
      // Add your models here
    ],
  );

  await sequelize.close();
}

Models & Tables​

Models in Sequelize Dart are defined using annotations. Here's a basic example:

import 'package:sequelize_orm/sequelize_orm.dart';

part 'users.model.g.dart';

@Table()
class User {
  @PrimaryKey()
  @AutoIncrement()
  DataType id = DataType.INTEGER;

  @NotNull()
  DataType username = DataType.STRING;

  @ColumnName('is_active')
  DataType isActive = DataType.BOOLEAN;

  static UserModel get model => UserModel();
}

Generating Model Code​

We recommend using our optimized CLI for faster code generation:

dart run sequelize_orm_generator:generate

Alternatively, you can use standard build_runner:

dart run build_runner build --delete-conflicting-outputs

This generates the *.model.g.dart file that contains the model implementation.

Basic Querying​

Create a Record​

final newUser = await User.model.create({
  'username': 'johndoe',
  'isActive': true,
});

Find Records​

// Find all users
final users = await User.model.findAll();

// Find one user
final user = await User.model.findOne(
  where: User.model.id.equals(1),
);

Update a Record​

await User.model.update(
  data: {'isActive': false},
  where: User.model.id.equals(1),
);

Complete Example​

Here's a complete example putting it all together:

import 'package:sequelize_orm/sequelize_orm.dart';
import 'package:sequelize_orm_example/db/models/user.model.dart';

const connectionString = 'postgresql://postgres:postgres@localhost:5432/postgres';

Future<void> main() async {
  // Create Sequelize instance
  final sequelize = Sequelize().createInstance(
    connection: SequelizeConnection.postgres(url: connectionString),
    logging: (sql) => SqlFormatter.printFormatted(sql),
  );

  // Initialize with models
  await sequelize.initialize(
    models: [
      User.model,
    ],
  );

  // Create a new user
  final newUser = await User.model.create({
    'username': 'johndoe',
    'isActive': true,
  });

  // Find the user
  final user = await User.model.findOne(
    where: User.model.id.equals(newUser.id),
  );

  print('Found user: ${user?.username}');

  // Update the user
  await User.model.update(
    data: {'isActive': false},
    where: User.model.id.equals(newUser.id),
  );

  // Find all users
  final allUsers = await User.model.findAll();
  print('Total users: ${allUsers.length}');

  // Close connection
  await sequelize.close();
}

Next Steps​