Question

I have several Rails Active Record Models: ContactEmails, ContactCalls, ContactPostalcards.

Each one represent a completed activity: a completed email, call, or postalcard to a specific Contact, and each Contact belongs to a Company.

I want a high-level summary by Company of all the Emails, Calls, and Postalcards within a specific date range:

def self.get_list(report_start_date, report_end_date)

    self.find :all,
      :select => "companies.name AS co_name, 
              companies.id AS comp_id, 
              COUNT(contact_emails.id) AS email_count, 
              COUNT(contact_calls.id) AS call_count, 
              COUNT(contact_letters.id) AS letter_count, 
              COUNT(contact_postalcards.id) AS postalcard_count",

      :conditions => ['contact_emails.date_sent < ? and contact_emails.date_sent > ? or
                       contact_calls.date_sent < ? and contact_calls.date_sent > ?', 
                  report_end_date, report_start_date, report_end_date, report_start_date],

      :joins => [
        "LEFT JOIN companies ON companies.id = contacts.company_id",
        "LEFT JOIN contact_emails ON contact_emails.contact_id = contacts.id",
        "LEFT JOIN contact_letters ON contact_letters.contact_id = contacts.id",
        "LEFT JOIN contact_postalcards ON contact_postalcards.contact_id = contacts.id",
        "LEFT JOIN contact_calls ON contact_calls.contact_id = contacts.id"
       ],
     #:group => "companies.id"
      :group => "companies.name"
  end

This is how I output the matrix in my View:

<% @matrix_summary.each do |item| %>      
<tr>
   <td><%= link_to item.co_name, company_path(item.comp_id) %></td>
   <td><%= item.email_count %> </td>
   <td><%= item.postalcard_count %></td>
   <td><%= item.call_count %></td>
<% end %>
</tr>

My expectation is each row should represent a Company, with the respective Email, Postalcard and Call counts for that one company (across all Contacts).

What I get is the same value (and a wrong value at that) for all Activities.

What am I doing that’s not right?

Answer 1

If you have few companies, than @klew’s suggestion is probably the way to go. If you have many and only want to run one query, here’s a gist which illustrates using subqueries to get all of the counts: http://gist.github.com/602944

It’s split into two examples, the first is really introductory to how the subqueries will work, the second removes all the redundancy so it’s easier to edit in the future.