180. 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 aboveLogs table, 1 is the only number that appears consecutively for at least three times.

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

Solution:

SELECT DISTINCT l1.Num As ConsecutiveNums 
FROM Logs l1
Join Logs l2 On L2.Id = L1.Id-1
Join Logs l3 On L3.Id = L1.Id-2
WHERE L1.Num=L2.Num and L1.Num=L3.Num;