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.
# Write your MySQL query statement below
SELECT DISTINCT Num FROM (
SELECT Num,
@cnt := IF(@prevNum = Num, @cnt, 0),
@cnt := @cnt + 1 as Cnt,
@prevNum := Num
FROM Logs s, (SELECT @cnt := 0) r, (SELECT @prevNum := NULL) p
ORDER BY Id ASC
) t where Cnt >= 3 ;