Leetcode:Consecutive Numbers

Write a SQL query to find all numbers that appear at least three times consecutively.

+----+-----+| Id | Num |+----+-----+| 1  |  1  || 2  |  1  || 3  |  1  || 4  |  2  || 5  |  1  || 6  |  2  || 7  |  2  |+----+-----+

For example, given the above Logs table, 1 is the only number that appears consecutively for at least three times.

思路：用户自定义变量

select distinct Numfrom(select Num,@cur := if(@pre=Num,@cur + 1,1) as times,@pre:=Num     from Logs,(Select @pre:=NULL) p) twhere times >=3;