Rails Migration: How to increase column data type size by using ROR migration

Solution 1:

class YourMigration < ActiveRecord::Migration
  def up
    change_column :users, :login, :string, :limit => 55
  end

  def down
    change_column :users, :login, :string, :limit => 40
  end
end

Solution 2:

class YourMigration < ActiveRecord::Migration
  def change
    change_column :users, :login, :string, :limit => 55
  end
end