SELECT Latest　取得最近的信息

SELECT    beyond_id,    year_month,    detail_infoFROM    t_beyond bINNER JOIN(    SELECT        beyond_id,        MAX(year_month) AS year_month    FROM        t_beyond    WHERE        year_month <= '20100912'    GROUP BY        beyond_id) mON    b.beyond_id = m.beyond_idAND    b.year_month = m.year_month