Unit.transaction do
  Unit.defaults.order(Unit.arel_table[:base_id].eq(nil)).delete_all
  units = {}
<% Unit.defaults.ordered.each do |unit| %>
<%= "\n" if unit.base.nil? %>
  units['<%= unit.symbol %>'] =
    Unit.create symbol: '<%= unit.symbol %>',<% unless unit.base.nil? %> base: units['<%= unit.base.symbol %>'], multiplier: '<%= unit.multiplier.to_scientific %>',<% end %>
                description: '<%= unit.description %>'
<% end %>
end