is it a normal Active Record bahaviour?

[eluser]brazilius[/eluser]
This piece of code

Code:

$data=array(
            'email'    =>    $this->session->userdata( 'email' ),
        'password'    =>     $this->session->userdata( 'password' ),
        'active' => 1
        );
$this->db->get_where('users',$data);
echo $this->db->last_query();

if userdata for email and password wasn't set
both values would be FALSE
and query would be
SELECT * FROM (`users`) WHERE `email` = 0 AND `password` = 0 AND `active` = 1
and all rows with active = 1 are selected (i can't get why)

and if you use mysql_real_escape_string on both values from session
you get the right query
SELECT * FROM (`users`) WHERE `email` = '' AND `password` = '' AND `active` = 1

is it a right behaviour or a bug&