如何从CodeIgniter中具有相同列名的表中输出数据？

This is my query:

这是我的查询:

$query = $this->db->query('
    SELECT archives.id, archives.signature, type_of_source.description, media_type.description, origin.description 
    FROM archives, type_of_source, media_type, origin                                                             
    WHERE archives.type_of_source_id = type_of_source.id                                                          
    AND type_of_source.media_type_id = media_type.id                                                              
    AND archives.origin_id = origin.id                                                                            
    ORDER BY archives.id ASC
');
$query = $this->d