2개 테이블에서 중복된거라도 한개씩만 추출하기 입니다.

select count( a.mb_id ) AS cnt,a.mb_id, b.mb_nick, b.mb_name, b.mb_email, b.mb_homepage, b.mb_open, a.lo_ip, a.lo_location, a.lo_url
           from g4_login a left join g4_member b on (a.mb_id = b.mb_id)

GROUP BY a.mb_id
HAVING cnt >=1

          order by a.lo_datetime desc