mysql 查询某时间段内连续n天登陆人数

//30多万条数据0.4秒 不到，查询某时间段内连续登陆n天的用户，1132条

SET @wy=0;

SELECT DISTINCT uid

FROM (SELECT MAX(date)-MIN(date) less,uid

    FROM (SELECT date-rn diff, uid, date, rn

        FROM (SELECT @wy:=@wy+1 rn, uid,

            datediff(login_time,'1971-01-01') date,login_time

            FROM (SELECT date(LOGINDATE) login_time, GUID uid FROM login_115_tab

                WHERE LOGINDATE>='2016-03-01 00:00:00' AND LOGINDATE <'2016-03-30 00:00:00'

                GROUP BY GUID, date(LOGINDATE)

            ORDER BY uid, date(login_time)

            ) as a

        )as b

    )as c

GROUP BY diff,uid

)as d

WHERE less>=6;