Fluent MySQL

Fluent MySQL (vapor/fluent-mysql) is a type-safe, fast, and easy-to-use ORM for MySQL built on top of Fluent.

!!! seealso The Fluent MySQL package is built on top of Fluent and the pure Swift, NIO-based MySQL core. You should refer to their guides for more information about subjects not covered here.

Getting Started

This section will show you how to add Fluent MySQL to your project and create your first MySQLModel.

Package

The first step to using Fluent MySQL is adding it as a dependency to your project in your SPM package manifest file.

  1. // swift-tools-version:4.0
  2. import PackageDescription
  4. let package = Package(
  5.     name: "MyApp",
  6.     dependencies: [
  7.         /// Any other dependencies ...
  9.         // 🖋🐬 Swift ORM (queries, models, relations, etc) built on MySQL.
  10.         .package(url: "https://github.com/vapor/fluent-mysql.git", from: "3.0.0-rc"),
  11.     ],
  12.     targets: [
  13.         .target(name: "App", dependencies: ["FluentMySQL", ...]),
  14.         .target(name: "Run", dependencies: ["App"]),
  15.         .testTarget(name: "AppTests", dependencies: ["App"]),
  16.     ]
  17. )

Don’t forget to add the module as a dependency in the targets array. Once you have added the dependency, regenerate your Xcode project with the following command:

  1. vapor xcode

Model

Now let’s create our first MySQLModel. Models represent tables in your MySQL database and they are the primary method of interacting with your data. 

  1. /// A simple user.
  2. final class User: MySQLModel {
  3.     /// The unique identifier for this user.
  4.     var id: Int?
  6.     /// The user's full name.
  7.     var name: String
  9.     /// The user's current age in years.
  10.     var age: Int
  12.     /// Creates a new user.
  13.     init(id: Int? = nil, name: String, age: Int) {
  14.         self.id = id
  15.         self.name = name
  16.         self.age = age
  17.     }
  18. }

The example above shows a MySQLModel for a simple model representing a user. You can make both structs and classes a model. You can even conform types that come from external modules. The only requirement is that these types conform to Codable, which must be declared on the base type for synthesized (automatic) conformance.

Standard practice with MySQL databases is using an auto-generated INTEGER for creating and storing unique identifiers in the id column. It’s also possible to use UUIDs or even Strings for your identifiers. There are convenience protocol for that.

protocol type key
MySQLModel Int id
MySQLUUIDModel UUID id
MySQLStringModel String id

!!! seealso Take a look at Fluent → Model for more information on creating models with custom ID types and keys.

Migration

All of your models (with some rare exceptions) should have a corresponding table—or schema—in your database. You can use a Fluent → Migration to automatically generate this schema in a testable, maintainable way. Fluent makes it easy to automatically generate a migration for your model

!!! tip If you are creating models to represent an existing table or database, you can skip this step.

  1. /// Allows `User` to be used as a migration.
  2. extension User: Migration { }

That’s all it takes. Fluent uses Codable to analyze your model and will attempt to create the best possible schema for it.

Take a look at Fluent → Migration if you are interested in customizing this migration.

Configure

The final step is to configure your database. At a minimum, this requires adding two things to your configure.swift file.

  • FluentMySQLProvider
  • MigrationConfig

Let’s take a look.

  1. import FluentMySQL
  3. /// ...
  5. /// Register providers first
  6. try services.register(FluentMySQLProvider())
  8. /// Configure migrations
  9. var migrations = MigrationConfig()
  10. migrations.add(model: User.self, database: .mysql)
  11. services.register(migrations)
  13. /// Other services....

Registering the provider will add all of the services required for Fluent MySQL to work properly. It also includes a default database config struct that uses typical development environment credentials.

You can of course override this config struct if you have non-standard credentials.

  1. /// Register custom MySQL Config
  2. let mysqlConfig = MySQLDatabaseConfig(hostname: "localhost", port: 3306, username: "vapor")
  3. services.register(mysqlConfig)

Once you have the MigrationConfig added, you should be able to run your application and see the following:

  1. Migrating mysql DB
  2. Migrations complete
  3. Server starting on http://localhost:8080

Query

Now that you have created a model and a corresponding schema in your database, let’s make your first query.

  1. router.get("users") { req in
  2.     return User.query(on: req).all()
  3. }

If you run your app, and query that route, you should see an empty array returned. Now you just need to add some users! Congratulations on getting your first Fluent MySQL model and migration working.

Connection

With Fluent, you always have access to the underlying database driver. Using this underlying driver to perform a query is sometimes called a “raw query”.

Let’s take a look at a raw MySQL query.

  1. router.get("mysql-version") { req -> Future<String> in
  2.     return req.withPooledConnection(to: .mysql) { conn in
  3.         return try conn.query("select @@version as v;").map(to: String.self) { rows in
  4.             return try rows[0].firstValue(forColumn: "v")?.decode(String.self) ?? "n/a"
  5.         }
  6.     }
  7. }

In the above example, withPooledConnection(to:) is used to create a connection to the database identified by .mysql. This is the default database identifier. See Fluent → Database to learn more.

Once we have the MySQLConnection, we can perform a query on it. You can learn more about the methods available in MySQL → Core.