# 0180. Consecutive Numbers

https://leetcode.com/problems/consecutive-numbers

## Description

Table: `Logs`

```
+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| id          | int     |
| num         | varchar |
+-------------+---------+
id is the primary key for this table.
```

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

Return the result table in **any order**.

The query result format is in the following example.

**Example 1:**

```
**Input:** 
Logs table:
+----+-----+
| Id | Num |
+----+-----+
| 1  | 1   |
| 2  | 1   |
| 3  | 1   |
| 4  | 2   |
| 5  | 1   |
| 6  | 2   |
| 7  | 2   |
+----+-----+
**Output:** 
+-----------------+
| ConsecutiveNums |
+-----------------+
| 1               |
+-----------------+
**Explanation:** 1 is the only number that appears consecutively for at least three times.
```

## ac

```java
# Write your MySQL query statement below
select distinct Num ConsecutiveNums from (
select
Num,
case
    when @prev = Num then @cnt := @cnt + 1
    when (@prev := Num) is not null then @cnt := 1
end cnt
from Logs l, (Select @cnt := 1, @prev := NULL) c
) a
where a.cnt >= 3
```
