title: Join tables when searching using Sunspot/Solr in Rails 3
body: <p>I have an ActiveRecord model Products with associated Suppliers (via belongs_to/has_many association). I am using Sunspot for full-text searching. I make a search with that code:</p>
  
  <pre><code>@search = Products.search do
    fulltext params[:search]
  end
  @products = @search.results
  </code></pre>
  
  <p>But I'd like to include suppliers too, so every time I call, for example,</p>
  
  <pre><code>@products.first.supplier
  </code></pre>
  
  <p>it wouldn't make a new request to the database. I tried to use</p>
  
  <pre><code>@search = Products.search(include: :supplier) do
  </code></pre>
  
  <p>but it didn't help. Is there any possible way to do that in Sunspot?</p>