我用codeIgniter的活动记录类查询MySQL数据库。我需要选择表中的行，其中一个字段设置为NULL：

  $这个 - ＆GT; DB-化合物其中（存档=！'，'空'）;
$ Q = $这个 - ＆GT; DB-＆GT;获得（项目）;
 

这仅返回此查询：

  SELECT * FROM WHERE存档='NULL'项目！;
 

在存档字段是 DATE 字段。

有没有更好的办法来解决这个问题？我知道我可以只编写查询自己，但我wan't在我的code的活动记录要坚持。

 其中（存档IS NOT NULL'，空，假）
 

I'm using CodeIgniter's Active Record class to query the MySQL database. I need to select the rows in a table where a field is not set to NULL:

$this->db->where('archived !=', 'NULL');
$q = $this->db->get('projects');

That only returns this query:

SELECT * FROM projects WHERE archived != 'NULL';

The archived field is a DATE field.

Is there a better way to solve this? I know I can just write the query myself, but I wan't to stick with the Active Record throughout my code.

where('archived IS NOT NULL', null, false)