> For the complete documentation index, see [llms.txt](https://cfmigrations.ortusbooks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cfmigrations.ortusbooks.com/usage/seeders.md).

# Seeders

Seeding your database is an optional step that allows you to add data to your database in mass. It is usually used in development to create a populated environment for testing. Seeders should not be used for data required to run your application or to migrate data between columns. Seeders should be seen as entirely optional. If a seeder is never ran, your application should still work.

Seeders can be ran by calling the `seed` method on a `MigrationService`. It takes an optional `seedName` string to only run a specific seeder. Additionally, you can run all your seeders when migrating your database by passing `seed = true` to the `up` method.

By default, seeders can only be ran in `development` environments. This can be configured on each `manager` by setting a `seedEnvironments` key to either a list or array of allowed environments to run in.

A seeder is a cfc file with a single required method - `run`. For the `QBMigrationManager`, it is passed a `QueryBuilder` instance and a `MockData` instance, useful for creating fake data to insert into your database. (Other Migration Managers will have other arguments passed. Please refer to the documentation for your specific manager.)

```cfc
component {

    function run( qb, mockdata ) {
        qb.table( "users" ).insert(
            mockdata.mock(
                $num = 25,
                "firstName": "fname",
                "lastName": "lname",
                "email": "email",
                "password": "string-secure"
            )
        );
    }

}
```


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