Trouble getting child table information based on locale

I have two tables

manufacturers manuf_details (details are in several languages) id id name manufacturer_id . details . locale .

I have two models

Manufacturer Manuf_details has_one :manuf_detail belongs_to :manufacturer

I want to get all the info from the manufacturers table and the details from the manuf_details table for a specific locale and manufacturer.

In the controller I have the following:

@manufacturer = Manufacturer.find(:first, :conditions => {:id => params[:id]})

In the view I have the following

<%= @manufacturer.name %> <%= @manufacturer.manuf_detail.details%>

Rails automatically generates the sql to get the info from the details table for the view as in: SELECT * FROM `manuf_descriptions` WHERE (`manuf_descriptions`.manufacturer_id = 4) LIMIT 1

But what I need is it to generate the following: SELECT * FROM `manuf_descriptions` WHERE (`manuf_descriptions`.manufacturer_id = 4AND 'manuf_descriptions'.locale = 'EN') LIMIT 1

Or if the user selected say FRENCH it would be SELECT * FROM `manuf_descriptions` WHERE (`manuf_descriptions`.manufacturer_id = 4AND 'manuf_descriptions'.locale = 'FR') LIMIT 1

I tried to do a join as in the following:

find(:first, :joins => :manuf_description, :conditions => {:id => manufacturer_id, :manuf_descriptions => {:locale => I18n.locale}})

however this does not help because the line

<%= @manufacturer.manuf_detail.details%> in the view still gets generated by rails into

SELECT * FROM `manuf_descriptions` WHERE (`manuf_descriptions`.manufacturer_id = 4) LIMIT 1

How can I solve this?

Thank you in advance