mysql如何查找连续出现n次以上的数

select distinct(l1.num) as ConsecutiveNums  
from Logs l1,Logs l2,Logs l3
where 
l1.id=l2.id-1 and l1.id=l3.id-2 
and l1.num=l2.num and l1.num =l3.num

select  distinct(num) as ConsecutiveNums from 
(
select id,num,
if(@lastNum!=num,@group:=@group+1,@group) as g,
if(@lastNum!=num,@lastNum:=num,@lastNum) as c  from 
(select id,num from Logs )a,
(select @lastNum:=0,@group:=0 )b  
) m group by g  having count(1)>=3  order by id 

SELECT keyword, count( * ) AS count  
FROM article_keyword  
GROUP BY keyword  
ORDER BY count DESC  
LIMIT 20  

SELECT DISTINCT count( * ) AS count  
FROM article_keyword  
GROUP BY keyword  
ORDER BY count DESC  
LIMIT 6