180. Consecutive Numbers (Medium)

Source: https://leetcode.com/problems/consecutive-numbers/#/description
Description:

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.

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

 

Solution:

select distinct l1.num
from Logs l1 
    join Logs l2 on l1.id=l2.id-1 
    join Logs l3 on l1.id=l3.id-2
where l1.num=l2.num and l2.num=l3.num