Rails-like rake db:migrate with sequel

sequel_migrations.rb

# Rakefile
namespace :db do
  desc "Run migrations"
  task :migrate, [:version] do |t, args|
    require "sequel"
    Sequel.extension :migration
    db = Sequel.connect(ENV.fetch("DATABASE_URL"))
    if args[:version]
      puts "Migrating to version #{args[:version]}"
      Sequel::Migrator.run(db, "db/migrations", target: args[:version].to_i)
    else
      puts "Migrating to latest"
      Sequel::Migrator.run(db, "db/migrations")
    end
  end

  desc "Rollback migration"
  task :rollback, [:version] do |t, args|
    require "sequel"
    Sequel.extension :migration
    db = Sequel.connect(ENV.fetch("DATABASE_URL"))
    version = args[:version] || db[:schema_info].first[:version] - 1
    if version
      puts "Rolling back to version #{version}"
      Sequel::Migrator.run(db, "db/migrations", target: version.to_i)
    end
  end
end