Creating a foreign data wrapper with Postgres and Sequel

005_add_vat_rates.rb

# NOTE: several improvements to be made but I'm in a VAT preparation hurry
# - use "up" and "down" to make the migration reversible
# - use Sequel methods for extension/server create
Sequel.migration do
  change do
    file = File.expand_path(File.join(File.dirname(__FILE__), '..', 'data', 'vat_rates.csv'))
    run 'CREATE EXTENSION file_fdw;'
    run 'CREATE SERVER file_fdw_server FOREIGN DATA WRAPPER file_fdw;'
    create_table(:vat_rates, foreign: 'file_fdw_server', options: {format: 'csv', header: 'true', filename: file, delimiter: ','}) do
      String :month, null: false
      String :bulletin, null: false
      BigDecimal :usd_for_one_eur, null: false
    end
    # nope, you can't create an index for foreign data wrappers
    # add_index :vat_rates, :month, unique: true
  end
end