zend-framework - zend framework db limit

¿Cómo puedo unirme a una subconsulta usando Zend_Db_Select?

Question

¿Cómo construiría esta consulta usando Zend_Db_Select? :

SELECT users.user_id, email_address, t1.value as ''languages''
FROM users
LEFT JOIN (
SELECT
user_id
, field_id
, GROUP_CONCAT(value SEPARATOR '','') AS value
FROM user_multivalued
WHERE field_id=25
GROUP BY user_id, field_id) t1
ON t1.user_id = users.users_id
WHERE list_id = 45

Answer 1

$user_multivalued = $db
->select()
->from(''user_multivalued'', array(
''user_id'',
''field_id'',
new Zend_Db_Expr("GROUP_CONCAT(value SEPARATOR '','') AS value")
))
->where(''field = ?'', 25)
->group(''user_id'')
->group(''field_id'')
;
$select = $db
->select()
->from(''users'', array(''user_id'', ''email_address''))
->joinLeft(
array(''t1'' => $user_multivalued),
''t1.user_id = users.user_id'',
array(''languages''=>''value'')
)
->where(''list_id = ?'', 45)
;