Seeding

• Getting Started
• Creating Seeder
• Running Seeder

You can use a seeder class to quickly populate your database with some dummy data. This is very useful during testing as well as for demo apps. Coupled with an Entity Factory, this is a very powerful tool to quickly cook up some test data.

Getting Started

A seeder is just a class, or an object, extending the abstract dev.alpas.ozone.Seeder class. The extending class is required to override the only abstract method — run().

The run() methods receives an instance of Application to make it easier for you to resolve dependencies, if any. Inside the run() method, you can populate your data and insert them into a database in any way you want. However, you may want to hook it up with an Entity Factory for quickly creating entity instances.

/info/A seeder can be named anything but they usually end with the suffix Seeder. They are also conventionally kept in database/seeds folder.

Creating a Seeder

You can create a seeder by extending the abstract Seeder class or use make:seeder command to create one or multiple seeders in a jiffy.

# creates 3 seeders under database/seeds folder
$ alpas make:seeder ArticlesSeeder UsersSeeder CommentsSeeder

internal class ArticlesSeeder : Seeder() {
    override fun run(app: Application) {
        // Do something
    }
}

Running a Seeder

You can run a seeder by using the db:seed Alpas console command. This command optionally takes the name of the seeder to run. If no name is passed, it runs the DatabaseSeeder class. If this class doesn't exist, then it will throw an error.

# Runs the default DatabaseSeeder
$ alpas db:seed 

# Runs the ArticlesSeeder
$ alpas db:seed ArticlesSeeder

You can run multiple seeders by calling their run() methods from another seeder's run() method. Here is an example of running 3 seeders from within a DatabaseSeeder class.

internal class DatabaseSeeder : Seeder() {
    override fun run(app: Application) {
        UsersSeeder().run(app)
        ArticlesSeeder().run(app)
        CommentsSeeder().run(app)
    }
}

Now, if you run the DatabaseSeeder by using alpas db:seed, it will effectively run UserSeeder, ArticleSeeder, and CommentSeeder.