LeetCode: 180. Consecutive Numbers
题目描述
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 |
+-----------------+解题思路
将三个 logs 表链接，然后筛选出符合要求的内容。
AC 代码
SELECT DISTINCT logs1.num AS ConsecutiveNums
FROM logs AS logs1, logs AS logs2, logs As logs3
WHERE logs1.Id = logs2.Id+1 AND logs2.Id = logs3.Id+1 AND logs1.Num = logs2.Num AND logs2.Num = logs3.Num