如何在rails中添加WHERE语句：select？

Question

我有当前的查找语句：select：

@list = Contact.find :all,
  :select => "companies.name AS co_name,  
              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,",
  :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"

我只想列举那些contact_email，contact_letters等具有date_sent <report_end_date和date_sent> report_start_date的实例。

我怎么做？

Answer 1

通过添加conditions 。 例如：

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