codeigniter dodając IS NULL w find_in_set

Poniżej kod 100% work.spróbuj,

    $this->db->select('id,memo,sent_to,sent_by,read_by,date');
    $this->db->from('memos');
    $this->db->where("FIND_IN_SET('1',`sent_to`) !=", 0);
    $this->db->order_by('`id`','DESC');
    $this->db->get();