编写一个 SQL 查询，查找所有至少连续出现三次的数字。

  1. +----+-----+
  2. | Id | Num |
  3. +----+-----+
  4. | 1  |  1  |
  5. | 2  |  1  |
  6. | 3  |  1  |
  7. | 4  |  2  |
  8. | 5  |  1  |
  9. | 6  |  2  |
  10. | 7  |  2  |
  11. +----+-----+

例如，给定上面的 Logs 表， 1 是唯一连续出现至少三次的数字。

+-----------------+
| ConsecutiveNums |
+-----------------+
| 1               |
+-----------------+

解决思路：一开始没有想到，是查看别人SQL进行写出来的，特地学习一下：

LeetCode180-MySQL-连续出现的数字

https://blog.csdn.net/qq_41822173/article/details/80957895
就是通过判断id是否连续，然后Num值是否相等。
我的SQL：

SELECT
    l1.Num ConsecutiveNums
FROM
    LOGS l1,
    LOGS l2,
    LOGS l3
WHERE
    l1.id = l2.id - 1
AND l2.id = l3.id - 1
AND l1.Num = l2.Num
AND l2.Num = l3.Num
GROUP BY l1.Num

其他SQL：

示例一：SELECT distinct num as ConsecutiveNums FROM(
SELECT id, num, 
@pre := @cur,
@cur := num,
@rep_ct := IF(@pre = @cur, @rep_ct + 1, 1) as rep_ct
FROM `Logs` l, (SELECT @pre := null, @cur := 0, @rep_ct := 1) init
) temp WHERE rep_ct >= 3

示例二：select distinct l1.num 'ConsecutiveNums' 
from logs l1, logs l2, logs l3
where l1.id - l2.id = 1
and l1.num = l2.num
and l2.id - l3.id = 1
and l2.num = l3.num;