I'm wondering if there's a clean way to acheive this using Doctrine.
Currently I'm just post-processing a record set filtered by one of my
requirements.  Basically I won't to complicate the following
documentation by restricting each side of the relationship to a
particular language:

http://www.doctrine-project.org/documentation/manual/1_1/en/defining-...

Ok, so I have an equal-nest relation, typically demoed as a User <->
Friend relationship, where the user can have many Friends, who are
actually Users from the same table.  Now, let's throw in a field on
User... lang_code: string(5).

So my schema might look like this:

----

User:
  columns:
    id:
      type: integer
      primary: true
      autoincrement: true
    username: string(255)
    lang_code: string(5)
  indexes:
    lang_index:
      fields: ['lang_code']
  relations:
    Friends:
      local: user_id1
      foreign: user_id2
      class: User
      refClass: Friendship
      equal: true
  options:
    type: INNODB
    collate: utf8_general_ci
    charset: utf8

Friendship:
  columns:
    user_id1:
      type: integer
      primary: true
    user_id2:
      type: integer
      primary: true
  options:
    type: INNODB
    collate: utf8_general_ci
    charset: utf8

----

I can easily get a User and all of their Friends:

$user = Doctrine_Query::create()
  ->select('u.*, RANDOM() r')
  ->from('User u')
  ->orderby('r')
  ->limit(1)
  ->fetchOne(1)
  ;

foreach ($user->Friends as $friend) {
  // whatever

Now, what if I say, I want a random Italian user who and all of their
English friends:

$user = Doctrine_Query::create()
  ->select('u.*, RANDOM() r')
  ->from('User u')
  // ->somehowJoin('User friend WITH friend.lang_code = ?', 'en_GB')
  ->where('u.lang_code = ?', 'it_IT')
  ->orderby('r')
  ->limit(1)
  ->fetchOne(1)
  ;

Is there a way to include these conditions in the query, or does it
come down to post-processing?

Cheers,