Making a RAW SQL connection and rendering JSON for custom auto complete field

In any model class

def self.labels_for_autocomplete(auto_c_req)
    connection.select_all("SELECT label FROM companies WHERE LOWER(label) LIKE '#{auto_c_req.downcase}%' ORDER BY label ASC LIMIT 10 ")
end

• The connection outpass ActiveRecords and does not cast results as Ruby objects.

In the controller

def suggest_entreprises
    if request.xhr?
        if request.post?
            auto_c_req=params[:auto_c_req]
            results=Company.labels_for_autocomplete auto_c_req
            render :json => results.to_json
        end
    end
    render :text => "Error"
end

• This example renders as JSON, and accepts only POST XHR requests.