嗨,我想将我正常的
mysql查询转换为zend.db.select;
我想使用这个脚本:
$select = $db->select(); // Add a FROM clause $select->from( ...specify table and columns... ) // Add a WHERE clause $select->where( ...specify search criteria... ) // Add an ORDER BY clause $select->order( ...specify sorting criteria... ); $select->limit(20,10);
我的查询如下
SELECT IF(derived_messages.toid = '$user',derived_messages.fromid,derived_messages.toid) friend1,c.UserName,derived_messages.message,derived_messages.toid,derived_messages.is_read,derived_messages.type,derived_messages.id as mesid,derived_messages.date,(SELECT M.message_id FROM messagesmapped M where M.message_id= derived_messages.id AND M.user_id ='$user' AND M.important = 1) as MesMapid FROM ( SELECT * FROM messages WHERE messages.deleted_by NOT IN ( $user ) ORDER BY Date DESC ) derived_messages INNER JOIN Users c ON c.MemberID = IF(derived_messages.toid = '$user',derived_messages.toid) WHERE (derived_messages.id IN (SELECT M.message_id FROM messagesmapped M where M.message_id= derived_messages.id AND M.user_id ='$user' AND M.important = 1) AND (derived_messages.toid='$user' OR derived_messages.fromid='$user')) GROUP BY friend1 ASC ORDER BY derived_messages.date DESC,derived_messages.id DESC LIMIT $limit $offset
我希望有人可以帮助我.
谢谢.
解决方法
这是可能的,但不太可能有人会为您编写查询.
我对解决此类查询的建议是将每个子查询编写为自己的Zend_Db_Select对象,然后使用已有对象的子查询构建最终查询.
Zend_Db_Select不直接支持IF函数,因此您需要使用Zend_Db_Expr
将该语句添加到您的选择中.
这是我所说的基本例子.让我们构建以下查询:
SELECT IF(msg.toId = 'drew010',msg.fromId,msg.toId),id,name,age,history.ip FROM users JOIN history ON users.id = history.userId WHERE users.id = ( SELECT id FROM users WHERE loginCount > 1000 ) GROUP BY id,ORDER BY age DESC
首先构建选择loginCount>用户的子选择. 1000.
$subquery1 = $db->select() ->from('users',array('id')) ->where('loginCount > ?',1000);
$cols = array( new Zend_Db_Expr('IF(' . $db->quoteInto('msg.toId = ?','drew010') . '),msg.toId'),'id','name','age' ); $query = $db->select() ->from('users',$cols) ->join('history','users.id = history.userId',array('ip')) ->where('id = ?',$subquery1) ->group('id') ->order('age DESC'); echo $query;
输出:
SELECT IF(msg.toId = 'drew010',`users`.`id`,`users`.`name`,`users`.`age`,`history`.`ip` FROM `users` INNER JOIN `history` ON users.id = history.userId WHERE id = ( (SELECT `users`.`id` FROM `users` WHERE (loginCount > 1000)) ) GROUP BY `id` ORDER BY `age` DESC
因此,首先要将整个查询分解为单个查询,然后构造外部查询.只要有耐心并慢慢来.然后阅读Zend_Db_Select
文档,全面了解您可以使用的内容.