`citext` pg column format is case insensitive: https://www.postgresql.org/docs/current/citext.html for ruby on rails migration

20210313000000_create_foos.rb

# citext pg column format is case insensitive: https://www.postgresql.org/docs/current/citext.html
class EnablePostgresExtensions < ActiveRecord::Migration[6.1]
  def change
    enable_extension 'citext'
  end
end

class CreateFoo < ActiveRecord::Migration[6.1]
  def change
    create_table :foos, id: :uuid do |t|
      t.citext    :bar, null: false, index: {unique: true}
      t.citext    :bar_id, null: false, index: {unique: true}

      t.timestamps
    end
  end
end