---
description: '# Medium'
---

# 180. Consecutive Numbers(SQL)

### Solution 1:

复制三个表格做内交，想象一下三张卡片，第二张比第一张往下位移1格，第三张比第一张往下位移2格，根据`num`相等相交出来的一行一定是连续重复了三次的数

### Solution 2:

建立三个表格，加上4个所有的限制条件，即为结果

```sql
# Write your MySQL query statement below
select distinct l1.Num ConsecutiveNums 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;

# 或者另一种方法
select distinct 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;
```

{% hint style="danger" %}
从这道题可以看出命名的规则比较明显，无论是表格还是列的命名都直接紧跟后面即可，表格重命名可以在前面的**select**关键词后面直接用
{% endhint %}
