如何在Zend_Db_Select中使用子查询进行连接

Question

我该如何使用Zend_Db_Select构建此查询语句？

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

- Oleg

---

看起来可以这样做： $subscribers->joinLeft(array($tableAlias => new Zend_Db_Expr('(' . $query . ')' )), $joinCondition, array($fieldInfo['name'] => 'value')); - Oleg

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)
;

- Stephen Fuhry

---

需要注意的是（在我尝试弄清楚这个问题之前让我感到困惑）： 在第一个joinLeft()参数中，确保将其作为Zend_Db_Expr对象传递，而不是其__toString()版本。 - Ariel Allon