我正在尝试使用 zend_db_select (ZF 1.12) 中的相关子查询构造一个有效的 MySql 查询,以在 Zend_Paginator_Adapter 中使用它。工作查询如下:
SELECT f.*, (SELECT (COUNT(p.post_id) - 1)
FROM `forum_topic_posts` AS p WHERE f.topic_id = p.topic_id) AS post_count
FROM `forum_topics` AS f WHERE f.forum_id = '2293'
ORDER BY post_count DESC, last_update DESC
所以我制定了:
$subquery = $db->select()
->from(array('p' => 'forum_topic_posts'), 'COUNT(*)')
->where('p.topic_id = f.topic_id');
$this->sql = $db->select()
->from(array('f' => 'forum_topics'), array('*', $subquery . ' as post_count'))
->where('forum_id=?', $forumId, Zend_Db::PARAM_INT)
->order('post_count ' . $orderDirection);
但是 Zend 在执行查询时停止并出现以下异常:
Zend_Db_Statement_Mysqli_Exception: Mysqli prepare error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SELECT COUNT(*) FROM forum_topic_posts AS p WHERE (p.topic_id = f.to' at line 1
我怎样才能让子查询工作?