原文链接: https://leetcode-cn.com/problems/human-traffic-of-stadium
英文原文
Table: Stadium
+---------------+---------+ | Column Name | Type | +---------------+---------+ | id | int | | visit_date | date | | people | int | +---------------+---------+ visit_date is the primary key for this table. Each row of this table contains the visit date and visit id to the stadium with the number of people during the visit. No two rows will have the same visit_date, and as the id increases, the dates increase as well.
Write an SQL query to display the records with three or more rows with consecutive id's, and the number of people is greater than or equal to 100 for each.
Return the result table ordered by visit_date in ascending order.
The query result format is in the following example.
Example 1:
Input: Stadium table: +------+------------+-----------+ | id | visit_date | people | +------+------------+-----------+ | 1 | 2017-01-01 | 10 | | 2 | 2017-01-02 | 109 | | 3 | 2017-01-03 | 150 | | 4 | 2017-01-04 | 99 | | 5 | 2017-01-05 | 145 | | 6 | 2017-01-06 | 1455 | | 7 | 2017-01-07 | 199 | | 8 | 2017-01-09 | 188 | +------+------------+-----------+ Output: +------+------------+-----------+ | id | visit_date | people | +------+------------+-----------+ | 5 | 2017-01-05 | 145 | | 6 | 2017-01-06 | 1455 | | 7 | 2017-01-07 | 199 | | 8 | 2017-01-09 | 188 | +------+------------+-----------+ Explanation: The four rows with ids 5, 6, 7, and 8 have consecutive ids and each of them has >= 100 people attended. Note that row 8 was included even though the visit_date was not the next day after row 7. The rows with ids 2 and 3 are not included because we need at least three consecutive ids.
中文题目
表：
Stadium
+---------------+---------+ | Column Name | Type | +---------------+---------+ | id | int | | visit_date | date | | people | int | +---------------+---------+ visit_date 是表的主键 每日人流量信息被记录在这三列信息中：序号 (id)、日期 (visit_date)、 人流量 (people) 每天只有一行记录，日期随着 id 的增加而增加
编写一个 SQL 查询以找出每行的人数大于或等于 100 且 id 连续的三行或更多行记录。
返回按 visit_date 升序排列的结果表。
查询结果格式如下所示。
Stadium table:
+------+------------+-----------+
| id | visit_date | people |
+------+------------+-----------+
| 1 | 2017-01-01 | 10 |
| 2 | 2017-01-02 | 109 |
| 3 | 2017-01-03 | 150 |
| 4 | 2017-01-04 | 99 |
| 5 | 2017-01-05 | 145 |
| 6 | 2017-01-06 | 1455 |
| 7 | 2017-01-07 | 199 |
| 8 | 2017-01-09 | 188 |
+------+------------+-----------+
Result table:
+------+------------+-----------+
| id | visit_date | people |
+------+------------+-----------+
| 5 | 2017-01-05 | 145 |
| 6 | 2017-01-06 | 1455 |
| 7 | 2017-01-07 | 199 |
| 8 | 2017-01-09 | 188 |
+------+------------+-----------+
id 为 5、6、7、8 的四行 id 连续，并且每行都有 >= 100 的人数记录。
请注意，即使第 7 行和第 8 行的 visit_date 不是连续的，输出也应当包含第 8 行，因为我们只需要考虑 id 连续的记录。
不输出 id 为 2 和 3 的行，因为至少需要三条 id 连续的记录。
通过代码
官方题解
方法：使用 JOIN 和 WHERE 子句【通过】
思路
在表 stadium 中查询人流量超过 100 的记录，将查询结果与其自身的临时表连接，再使用 WHERE 子句获得满足条件的记录。
算法
第一步：查询人流量超过 100 的记录，然后将结果与其自身的临时表连接。
[snippet1-MySQL]select distinct t1.* from stadium t1, stadium t2, stadium t3 where t1.people >= 100 and t2.people >= 100 and t3.people >= 100 ;
| id | date | people | id | date | people | id | date | people |
|----|------------|--------|----|------------|--------|----|------------|--------|
| 2 | 2017-01-02 | 109 | 2 | 2017-01-02 | 109 | 2 | 2017-01-02 | 109 |
| 3 | 2017-01-03 | 150 | 2 | 2017-01-02 | 109 | 2 | 2017-01-02 | 109 |
| 5 | 2017-01-05 | 145 | 2 | 2017-01-02 | 109 | 2 | 2017-01-02 | 109 |
| 6 | 2017-01-06 | 1455 | 2 | 2017-01-02 | 109 | 2 | 2017-01-02 | 109 |
| 7 | 2017-01-07 | 199 | 2 | 2017-01-02 | 109 | 2 | 2017-01-02 | 109 |
| 8 | 2017-01-08 | 188 | 2 | 2017-01-02 | 109 | 2 | 2017-01-02 | 109 |
| 2 | 2017-01-02 | 109 | 3 | 2017-01-03 | 150 | 2 | 2017-01-02 | 109 |
| 3 | 2017-01-03 | 150 | 3 | 2017-01-03 | 150 | 2 | 2017-01-02 | 109 |
| 5 | 2017-01-05 | 145 | 3 | 2017-01-03 | 150 | 2 | 2017-01-02 | 109 |
| 6 | 2017-01-06 | 1455 | 3 | 2017-01-03 | 150 | 2 | 2017-01-02 | 109 |
| 7 | 2017-01-07 | 199 | 3 | 2017-01-03 | 150 | 2 | 2017-01-02 | 109 |
| 8 | 2017-01-08 | 188 | 3 | 2017-01-03 | 150 | 2 | 2017-01-02 | 109 |
| 2 | 2017-01-02 | 109 | 5 | 2017-01-05 | 145 | 2 | 2017-01-02 | 109 |
| 3 | 2017-01-03 | 150 | 5 | 2017-01-05 | 145 | 2 | 2017-01-02 | 109 |
| 5 | 2017-01-05 | 145 | 5 | 2017-01-05 | 145 | 2 | 2017-01-02 | 109 |
| 6 | 2017-01-06 | 1455 | 5 | 2017-01-05 | 145 | 2 | 2017-01-02 | 109 |
| 7 | 2017-01-07 | 199 | 5 | 2017-01-05 | 145 | 2 | 2017-01-02 | 109 |
| 8 | 2017-01-08 | 188 | 5 | 2017-01-05 | 145 | 2 | 2017-01-02 | 109 |
| 2 | 2017-01-02 | 109 | 6 | 2017-01-06 | 1455 | 2 | 2017-01-02 | 109 |
| 3 | 2017-01-03 | 150 | 6 | 2017-01-06 | 1455 | 2 | 2017-01-02 | 109 |
| 5 | 2017-01-05 | 145 | 6 | 2017-01-06 | 1455 | 2 | 2017-01-02 | 109 |
| 6 | 2017-01-06 | 1455 | 6 | 2017-01-06 | 1455 | 2 | 2017-01-02 | 109 |
| 7 | 2017-01-07 | 199 | 6 | 2017-01-06 | 1455 | 2 | 2017-01-02 | 109 |
| 8 | 2017-01-08 | 188 | 6 | 2017-01-06 | 1455 | 2 | 2017-01-02 | 109 |
| 2 | 2017-01-02 | 109 | 7 | 2017-01-07 | 199 | 2 | 2017-01-02 | 109 |
| 3 | 2017-01-03 | 150 | 7 | 2017-01-07 | 199 | 2 | 2017-01-02 | 109 |
| 5 | 2017-01-05 | 145 | 7 | 2017-01-07 | 199 | 2 | 2017-01-02 | 109 |
| 6 | 2017-01-06 | 1455 | 7 | 2017-01-07 | 199 | 2 | 2017-01-02 | 109 |
| 7 | 2017-01-07 | 199 | 7 | 2017-01-07 | 199 | 2 | 2017-01-02 | 109 |
| 8 | 2017-01-08 | 188 | 7 | 2017-01-07 | 199 | 2 | 2017-01-02 | 109 |
| 2 | 2017-01-02 | 109 | 8 | 2017-01-08 | 188 | 2 | 2017-01-02 | 109 |
| 3 | 2017-01-03 | 150 | 8 | 2017-01-08 | 188 | 2 | 2017-01-02 | 109 |
| 5 | 2017-01-05 | 145 | 8 | 2017-01-08 | 188 | 2 | 2017-01-02 | 109 |
| 6 | 2017-01-06 | 1455 | 8 | 2017-01-08 | 188 | 2 | 2017-01-02 | 109 |
| 7 | 2017-01-07 | 199 | 8 | 2017-01-08 | 188 | 2 | 2017-01-02 | 109 |
| 8 | 2017-01-08 | 188 | 8 | 2017-01-08 | 188 | 2 | 2017-01-02 | 109 |
| 2 | 2017-01-02 | 109 | 2 | 2017-01-02 | 109 | 3 | 2017-01-03 | 150 |
| 3 | 2017-01-03 | 150 | 2 | 2017-01-02 | 109 | 3 | 2017-01-03 | 150 |
| 5 | 2017-01-05 | 145 | 2 | 2017-01-02 | 109 | 3 | 2017-01-03 | 150 |
| 6 | 2017-01-06 | 1455 | 2 | 2017-01-02 | 109 | 3 | 2017-01-03 | 150 |
| 7 | 2017-01-07 | 199 | 2 | 2017-01-02 | 109 | 3 | 2017-01-03 | 150 |
| 8 | 2017-01-08 | 188 | 2 | 2017-01-02 | 109 | 3 | 2017-01-03 | 150 |
| 2 | 2017-01-02 | 109 | 3 | 2017-01-03 | 150 | 3 | 2017-01-03 | 150 |
| 3 | 2017-01-03 | 150 | 3 | 2017-01-03 | 150 | 3 | 2017-01-03 | 150 |
| 5 | 2017-01-05 | 145 | 3 | 2017-01-03 | 150 | 3 | 2017-01-03 | 150 |
| 6 | 2017-01-06 | 1455 | 3 | 2017-01-03 | 150 | 3 | 2017-01-03 | 150 |
| 7 | 2017-01-07 | 199 | 3 | 2017-01-03 | 150 | 3 | 2017-01-03 | 150 |
| 8 | 2017-01-08 | 188 | 3 | 2017-01-03 | 150 | 3 | 2017-01-03 | 150 |
| 2 | 2017-01-02 | 109 | 5 | 2017-01-05 | 145 | 3 | 2017-01-03 | 150 |
| 3 | 2017-01-03 | 150 | 5 | 2017-01-05 | 145 | 3 | 2017-01-03 | 150 |
| 5 | 2017-01-05 | 145 | 5 | 2017-01-05 | 145 | 3 | 2017-01-03 | 150 |
| 6 | 2017-01-06 | 1455 | 5 | 2017-01-05 | 145 | 3 | 2017-01-03 | 150 |
| 7 | 2017-01-07 | 199 | 5 | 2017-01-05 | 145 | 3 | 2017-01-03 | 150 |
| 8 | 2017-01-08 | 188 | 5 | 2017-01-05 | 145 | 3 | 2017-01-03 | 150 |
| 2 | 2017-01-02 | 109 | 6 | 2017-01-06 | 1455 | 3 | 2017-01-03 | 150 |
| 3 | 2017-01-03 | 150 | 6 | 2017-01-06 | 1455 | 3 | 2017-01-03 | 150 |
| 5 | 2017-01-05 | 145 | 6 | 2017-01-06 | 1455 | 3 | 2017-01-03 | 150 |
| 6 | 2017-01-06 | 1455 | 6 | 2017-01-06 | 1455 | 3 | 2017-01-03 | 150 |
| 7 | 2017-01-07 | 199 | 6 | 2017-01-06 | 1455 | 3 | 2017-01-03 | 150 |
| 8 | 2017-01-08 | 188 | 6 | 2017-01-06 | 1455 | 3 | 2017-01-03 | 150 |
| 2 | 2017-01-02 | 109 | 7 | 2017-01-07 | 199 | 3 | 2017-01-03 | 150 |
| 3 | 2017-01-03 | 150 | 7 | 2017-01-07 | 199 | 3 | 2017-01-03 | 150 |
| 5 | 2017-01-05 | 145 | 7 | 2017-01-07 | 199 | 3 | 2017-01-03 | 150 |
| 6 | 2017-01-06 | 1455 | 7 | 2017-01-07 | 199 | 3 | 2017-01-03 | 150 |
| 7 | 2017-01-07 | 199 | 7 | 2017-01-07 | 199 | 3 | 2017-01-03 | 150 |
| 8 | 2017-01-08 | 188 | 7 | 2017-01-07 | 199 | 3 | 2017-01-03 | 150 |
| 2 | 2017-01-02 | 109 | 8 | 2017-01-08 | 188 | 3 | 2017-01-03 | 150 |
| 3 | 2017-01-03 | 150 | 8 | 2017-01-08 | 188 | 3 | 2017-01-03 | 150 |
| 5 | 2017-01-05 | 145 | 8 | 2017-01-08 | 188 | 3 | 2017-01-03 | 150 |
| 6 | 2017-01-06 | 1455 | 8 | 2017-01-08 | 188 | 3 | 2017-01-03 | 150 |
| 7 | 2017-01-07 | 199 | 8 | 2017-01-08 | 188 | 3 | 2017-01-03 | 150 |
| 8 | 2017-01-08 | 188 | 8 | 2017-01-08 | 188 | 3 | 2017-01-03 | 150 |
| 2 | 2017-01-02 | 109 | 2 | 2017-01-02 | 109 | 5 | 2017-01-05 | 145 |
| 3 | 2017-01-03 | 150 | 2 | 2017-01-02 | 109 | 5 | 2017-01-05 | 145 |
| 5 | 2017-01-05 | 145 | 2 | 2017-01-02 | 109 | 5 | 2017-01-05 | 145 |
| 6 | 2017-01-06 | 1455 | 2 | 2017-01-02 | 109 | 5 | 2017-01-05 | 145 |
| 7 | 2017-01-07 | 199 | 2 | 2017-01-02 | 109 | 5 | 2017-01-05 | 145 |
| 8 | 2017-01-08 | 188 | 2 | 2017-01-02 | 109 | 5 | 2017-01-05 | 145 |
| 2 | 2017-01-02 | 109 | 3 | 2017-01-03 | 150 | 5 | 2017-01-05 | 145 |
| 3 | 2017-01-03 | 150 | 3 | 2017-01-03 | 150 | 5 | 2017-01-05 | 145 |
| 5 | 2017-01-05 | 145 | 3 | 2017-01-03 | 150 | 5 | 2017-01-05 | 145 |
| 6 | 2017-01-06 | 1455 | 3 | 2017-01-03 | 150 | 5 | 2017-01-05 | 145 |
| 7 | 2017-01-07 | 199 | 3 | 2017-01-03 | 150 | 5 | 2017-01-05 | 145 |
| 8 | 2017-01-08 | 188 | 3 | 2017-01-03 | 150 | 5 | 2017-01-05 | 145 |
| 2 | 2017-01-02 | 109 | 5 | 2017-01-05 | 145 | 5 | 2017-01-05 | 145 |
| 3 | 2017-01-03 | 150 | 5 | 2017-01-05 | 145 | 5 | 2017-01-05 | 145 |
| 5 | 2017-01-05 | 145 | 5 | 2017-01-05 | 145 | 5 | 2017-01-05 | 145 |
| 6 | 2017-01-06 | 1455 | 5 | 2017-01-05 | 145 | 5 | 2017-01-05 | 145 |
| 7 | 2017-01-07 | 199 | 5 | 2017-01-05 | 145 | 5 | 2017-01-05 | 145 |
| 8 | 2017-01-08 | 188 | 5 | 2017-01-05 | 145 | 5 | 2017-01-05 | 145 |
| 2 | 2017-01-02 | 109 | 6 | 2017-01-06 | 1455 | 5 | 2017-01-05 | 145 |
| 3 | 2017-01-03 | 150 | 6 | 2017-01-06 | 1455 | 5 | 2017-01-05 | 145 |
| 5 | 2017-01-05 | 145 | 6 | 2017-01-06 | 1455 | 5 | 2017-01-05 | 145 |
| 6 | 2017-01-06 | 1455 | 6 | 2017-01-06 | 1455 | 5 | 2017-01-05 | 145 |
| 7 | 2017-01-07 | 199 | 6 | 2017-01-06 | 1455 | 5 | 2017-01-05 | 145 |
| 8 | 2017-01-08 | 188 | 6 | 2017-01-06 | 1455 | 5 | 2017-01-05 | 145 |
| 2 | 2017-01-02 | 109 | 7 | 2017-01-07 | 199 | 5 | 2017-01-05 | 145 |
| 3 | 2017-01-03 | 150 | 7 | 2017-01-07 | 199 | 5 | 2017-01-05 | 145 |
| 5 | 2017-01-05 | 145 | 7 | 2017-01-07 | 199 | 5 | 2017-01-05 | 145 |
| 6 | 2017-01-06 | 1455 | 7 | 2017-01-07 | 199 | 5 | 2017-01-05 | 145 |
| 7 | 2017-01-07 | 199 | 7 | 2017-01-07 | 199 | 5 | 2017-01-05 | 145 |
| 8 | 2017-01-08 | 188 | 7 | 2017-01-07 | 199 | 5 | 2017-01-05 | 145 |
| 2 | 2017-01-02 | 109 | 8 | 2017-01-08 | 188 | 5 | 2017-01-05 | 145 |
| 3 | 2017-01-03 | 150 | 8 | 2017-01-08 | 188 | 5 | 2017-01-05 | 145 |
| 5 | 2017-01-05 | 145 | 8 | 2017-01-08 | 188 | 5 | 2017-01-05 | 145 |
| 6 | 2017-01-06 | 1455 | 8 | 2017-01-08 | 188 | 5 | 2017-01-05 | 145 |
| 7 | 2017-01-07 | 199 | 8 | 2017-01-08 | 188 | 5 | 2017-01-05 | 145 |
| 8 | 2017-01-08 | 188 | 8 | 2017-01-08 | 188 | 5 | 2017-01-05 | 145 |
| 2 | 2017-01-02 | 109 | 2 | 2017-01-02 | 109 | 6 | 2017-01-06 | 1455 |
| 3 | 2017-01-03 | 150 | 2 | 2017-01-02 | 109 | 6 | 2017-01-06 | 1455 |
| 5 | 2017-01-05 | 145 | 2 | 2017-01-02 | 109 | 6 | 2017-01-06 | 1455 |
| 6 | 2017-01-06 | 1455 | 2 | 2017-01-02 | 109 | 6 | 2017-01-06 | 1455 |
| 7 | 2017-01-07 | 199 | 2 | 2017-01-02 | 109 | 6 | 2017-01-06 | 1455 |
| 8 | 2017-01-08 | 188 | 2 | 2017-01-02 | 109 | 6 | 2017-01-06 | 1455 |
| 2 | 2017-01-02 | 109 | 3 | 2017-01-03 | 150 | 6 | 2017-01-06 | 1455 |
| 3 | 2017-01-03 | 150 | 3 | 2017-01-03 | 150 | 6 | 2017-01-06 | 1455 |
| 5 | 2017-01-05 | 145 | 3 | 2017-01-03 | 150 | 6 | 2017-01-06 | 1455 |
| 6 | 2017-01-06 | 1455 | 3 | 2017-01-03 | 150 | 6 | 2017-01-06 | 1455 |
| 7 | 2017-01-07 | 199 | 3 | 2017-01-03 | 150 | 6 | 2017-01-06 | 1455 |
| 8 | 2017-01-08 | 188 | 3 | 2017-01-03 | 150 | 6 | 2017-01-06 | 1455 |
| 2 | 2017-01-02 | 109 | 5 | 2017-01-05 | 145 | 6 | 2017-01-06 | 1455 |
| 3 | 2017-01-03 | 150 | 5 | 2017-01-05 | 145 | 6 | 2017-01-06 | 1455 |
| 5 | 2017-01-05 | 145 | 5 | 2017-01-05 | 145 | 6 | 2017-01-06 | 1455 |
| 6 | 2017-01-06 | 1455 | 5 | 2017-01-05 | 145 | 6 | 2017-01-06 | 1455 |
| 7 | 2017-01-07 | 199 | 5 | 2017-01-05 | 145 | 6 | 2017-01-06 | 1455 |
| 8 | 2017-01-08 | 188 | 5 | 2017-01-05 | 145 | 6 | 2017-01-06 | 1455 |
| 2 | 2017-01-02 | 109 | 6 | 2017-01-06 | 1455 | 6 | 2017-01-06 | 1455 |
| 3 | 2017-01-03 | 150 | 6 | 2017-01-06 | 1455 | 6 | 2017-01-06 | 1455 |
| 5 | 2017-01-05 | 145 | 6 | 2017-01-06 | 1455 | 6 | 2017-01-06 | 1455 |
| 6 | 2017-01-06 | 1455 | 6 | 2017-01-06 | 1455 | 6 | 2017-01-06 | 1455 |
| 7 | 2017-01-07 | 199 | 6 | 2017-01-06 | 1455 | 6 | 2017-01-06 | 1455 |
| 8 | 2017-01-08 | 188 | 6 | 2017-01-06 | 1455 | 6 | 2017-01-06 | 1455 |
| 2 | 2017-01-02 | 109 | 7 | 2017-01-07 | 199 | 6 | 2017-01-06 | 1455 |
| 3 | 2017-01-03 | 150 | 7 | 2017-01-07 | 199 | 6 | 2017-01-06 | 1455 |
| 5 | 2017-01-05 | 145 | 7 | 2017-01-07 | 199 | 6 | 2017-01-06 | 1455 |
| 6 | 2017-01-06 | 1455 | 7 | 2017-01-07 | 199 | 6 | 2017-01-06 | 1455 |
| 7 | 2017-01-07 | 199 | 7 | 2017-01-07 | 199 | 6 | 2017-01-06 | 1455 |
| 8 | 2017-01-08 | 188 | 7 | 2017-01-07 | 199 | 6 | 2017-01-06 | 1455 |
| 2 | 2017-01-02 | 109 | 8 | 2017-01-08 | 188 | 6 | 2017-01-06 | 1455 |
| 3 | 2017-01-03 | 150 | 8 | 2017-01-08 | 188 | 6 | 2017-01-06 | 1455 |
| 5 | 2017-01-05 | 145 | 8 | 2017-01-08 | 188 | 6 | 2017-01-06 | 1455 |
| 6 | 2017-01-06 | 1455 | 8 | 2017-01-08 | 188 | 6 | 2017-01-06 | 1455 |
| 7 | 2017-01-07 | 199 | 8 | 2017-01-08 | 188 | 6 | 2017-01-06 | 1455 |
| 8 | 2017-01-08 | 188 | 8 | 2017-01-08 | 188 | 6 | 2017-01-06 | 1455 |
| 2 | 2017-01-02 | 109 | 2 | 2017-01-02 | 109 | 7 | 2017-01-07 | 199 |
| 3 | 2017-01-03 | 150 | 2 | 2017-01-02 | 109 | 7 | 2017-01-07 | 199 |
| 5 | 2017-01-05 | 145 | 2 | 2017-01-02 | 109 | 7 | 2017-01-07 | 199 |
| 6 | 2017-01-06 | 1455 | 2 | 2017-01-02 | 109 | 7 | 2017-01-07 | 199 |
| 7 | 2017-01-07 | 199 | 2 | 2017-01-02 | 109 | 7 | 2017-01-07 | 199 |
| 8 | 2017-01-08 | 188 | 2 | 2017-01-02 | 109 | 7 | 2017-01-07 | 199 |
| 2 | 2017-01-02 | 109 | 3 | 2017-01-03 | 150 | 7 | 2017-01-07 | 199 |
| 3 | 2017-01-03 | 150 | 3 | 2017-01-03 | 150 | 7 | 2017-01-07 | 199 |
| 5 | 2017-01-05 | 145 | 3 | 2017-01-03 | 150 | 7 | 2017-01-07 | 199 |
| 6 | 2017-01-06 | 1455 | 3 | 2017-01-03 | 150 | 7 | 2017-01-07 | 199 |
| 7 | 2017-01-07 | 199 | 3 | 2017-01-03 | 150 | 7 | 2017-01-07 | 199 |
| 8 | 2017-01-08 | 188 | 3 | 2017-01-03 | 150 | 7 | 2017-01-07 | 199 |
| 2 | 2017-01-02 | 109 | 5 | 2017-01-05 | 145 | 7 | 2017-01-07 | 199 |
| 3 | 2017-01-03 | 150 | 5 | 2017-01-05 | 145 | 7 | 2017-01-07 | 199 |
| 5 | 2017-01-05 | 145 | 5 | 2017-01-05 | 145 | 7 | 2017-01-07 | 199 |
| 6 | 2017-01-06 | 1455 | 5 | 2017-01-05 | 145 | 7 | 2017-01-07 | 199 |
| 7 | 2017-01-07 | 199 | 5 | 2017-01-05 | 145 | 7 | 2017-01-07 | 199 |
| 8 | 2017-01-08 | 188 | 5 | 2017-01-05 | 145 | 7 | 2017-01-07 | 199 |
| 2 | 2017-01-02 | 109 | 6 | 2017-01-06 | 1455 | 7 | 2017-01-07 | 199 |
| 3 | 2017-01-03 | 150 | 6 | 2017-01-06 | 1455 | 7 | 2017-01-07 | 199 |
| 5 | 2017-01-05 | 145 | 6 | 2017-01-06 | 1455 | 7 | 2017-01-07 | 199 |
| 6 | 2017-01-06 | 1455 | 6 | 2017-01-06 | 1455 | 7 | 2017-01-07 | 199 |
| 7 | 2017-01-07 | 199 | 6 | 2017-01-06 | 1455 | 7 | 2017-01-07 | 199 |
| 8 | 2017-01-08 | 188 | 6 | 2017-01-06 | 1455 | 7 | 2017-01-07 | 199 |
| 2 | 2017-01-02 | 109 | 7 | 2017-01-07 | 199 | 7 | 2017-01-07 | 199 |
| 3 | 2017-01-03 | 150 | 7 | 2017-01-07 | 199 | 7 | 2017-01-07 | 199 |
| 5 | 2017-01-05 | 145 | 7 | 2017-01-07 | 199 | 7 | 2017-01-07 | 199 |
| 6 | 2017-01-06 | 1455 | 7 | 2017-01-07 | 199 | 7 | 2017-01-07 | 199 |
| 7 | 2017-01-07 | 199 | 7 | 2017-01-07 | 199 | 7 | 2017-01-07 | 199 |
| 8 | 2017-01-08 | 188 | 7 | 2017-01-07 | 199 | 7 | 2017-01-07 | 199 |
| 2 | 2017-01-02 | 109 | 8 | 2017-01-08 | 188 | 7 | 2017-01-07 | 199 |
| 3 | 2017-01-03 | 150 | 8 | 2017-01-08 | 188 | 7 | 2017-01-07 | 199 |
| 5 | 2017-01-05 | 145 | 8 | 2017-01-08 | 188 | 7 | 2017-01-07 | 199 |
| 6 | 2017-01-06 | 1455 | 8 | 2017-01-08 | 188 | 7 | 2017-01-07 | 199 |
| 7 | 2017-01-07 | 199 | 8 | 2017-01-08 | 188 | 7 | 2017-01-07 | 199 |
| 8 | 2017-01-08 | 188 | 8 | 2017-01-08 | 188 | 7 | 2017-01-07 | 199 |
| 2 | 2017-01-02 | 109 | 2 | 2017-01-02 | 109 | 8 | 2017-01-08 | 188 |
| 3 | 2017-01-03 | 150 | 2 | 2017-01-02 | 109 | 8 | 2017-01-08 | 188 |
| 5 | 2017-01-05 | 145 | 2 | 2017-01-02 | 109 | 8 | 2017-01-08 | 188 |
| 6 | 2017-01-06 | 1455 | 2 | 2017-01-02 | 109 | 8 | 2017-01-08 | 188 |
| 7 | 2017-01-07 | 199 | 2 | 2017-01-02 | 109 | 8 | 2017-01-08 | 188 |
| 8 | 2017-01-08 | 188 | 2 | 2017-01-02 | 109 | 8 | 2017-01-08 | 188 |
| 2 | 2017-01-02 | 109 | 3 | 2017-01-03 | 150 | 8 | 2017-01-08 | 188 |
| 3 | 2017-01-03 | 150 | 3 | 2017-01-03 | 150 | 8 | 2017-01-08 | 188 |
| 5 | 2017-01-05 | 145 | 3 | 2017-01-03 | 150 | 8 | 2017-01-08 | 188 |
| 6 | 2017-01-06 | 1455 | 3 | 2017-01-03 | 150 | 8 | 2017-01-08 | 188 |
| 7 | 2017-01-07 | 199 | 3 | 2017-01-03 | 150 | 8 | 2017-01-08 | 188 |
| 8 | 2017-01-08 | 188 | 3 | 2017-01-03 | 150 | 8 | 2017-01-08 | 188 |
| 2 | 2017-01-02 | 109 | 5 | 2017-01-05 | 145 | 8 | 2017-01-08 | 188 |
| 3 | 2017-01-03 | 150 | 5 | 2017-01-05 | 145 | 8 | 2017-01-08 | 188 |
| 5 | 2017-01-05 | 145 | 5 | 2017-01-05 | 145 | 8 | 2017-01-08 | 188 |
| 6 | 2017-01-06 | 1455 | 5 | 2017-01-05 | 145 | 8 | 2017-01-08 | 188 |
| 7 | 2017-01-07 | 199 | 5 | 2017-01-05 | 145 | 8 | 2017-01-08 | 188 |
| 8 | 2017-01-08 | 188 | 5 | 2017-01-05 | 145 | 8 | 2017-01-08 | 188 |
| 2 | 2017-01-02 | 109 | 6 | 2017-01-06 | 1455 | 8 | 2017-01-08 | 188 |
| 3 | 2017-01-03 | 150 | 6 | 2017-01-06 | 1455 | 8 | 2017-01-08 | 188 |
| 5 | 2017-01-05 | 145 | 6 | 2017-01-06 | 1455 | 8 | 2017-01-08 | 188 |
| 6 | 2017-01-06 | 1455 | 6 | 2017-01-06 | 1455 | 8 | 2017-01-08 | 188 |
| 7 | 2017-01-07 | 199 | 6 | 2017-01-06 | 1455 | 8 | 2017-01-08 | 188 |
| 8 | 2017-01-08 | 188 | 6 | 2017-01-06 | 1455 | 8 | 2017-01-08 | 188 |
| 2 | 2017-01-02 | 109 | 7 | 2017-01-07 | 199 | 8 | 2017-01-08 | 188 |
| 3 | 2017-01-03 | 150 | 7 | 2017-01-07 | 199 | 8 | 2017-01-08 | 188 |
| 5 | 2017-01-05 | 145 | 7 | 2017-01-07 | 199 | 8 | 2017-01-08 | 188 |
| 6 | 2017-01-06 | 1455 | 7 | 2017-01-07 | 199 | 8 | 2017-01-08 | 188 |
| 7 | 2017-01-07 | 199 | 7 | 2017-01-07 | 199 | 8 | 2017-01-08 | 188 |
| 8 | 2017-01-08 | 188 | 7 | 2017-01-07 | 199 | 8 | 2017-01-08 | 188 |
| 2 | 2017-01-02 | 109 | 8 | 2017-01-08 | 188 | 8 | 2017-01-08 | 188 |
| 3 | 2017-01-03 | 150 | 8 | 2017-01-08 | 188 | 8 | 2017-01-08 | 188 |
| 5 | 2017-01-05 | 145 | 8 | 2017-01-08 | 188 | 8 | 2017-01-08 | 188 |
| 6 | 2017-01-06 | 1455 | 8 | 2017-01-08 | 188 | 8 | 2017-01-08 | 188 |
| 7 | 2017-01-07 | 199 | 8 | 2017-01-08 | 188 | 8 | 2017-01-08 | 188 |
| 8 | 2017-01-08 | 188 | 8 | 2017-01-08 | 188 | 8 | 2017-01-08 | 188 |
- 共有 6 天人流量超过 100 人，笛卡尔积 后有 216（666） 条记录。
- 前 3 列来自表 t1，中间 3 列来自表 t2，最后 3 列来自表 t3。
表 t1，t2 和 t3 相同，需要考虑添加哪些条件能够得到想要的结果。以 t1 为例，它有可能是高峰期的第 1 天，第 2 天，或第 3 天。
- t1 是高峰期第 1 天：
(t1.id - t2.id = 1 and t1.id - t3.id = 2 and t2.id - t3.id =1) -- t1, t2, t3 - t1 是高峰期第 2 天：
(t2.id - t1.id = 1 and t2.id - t3.id = 2 and t1.id - t3.id =1) -- t2, t1, t3 - t1 是高峰期第 3 天：
(t3.id - t2.id = 1 and t2.id - t1.id =1 and t3.id - t1.id = 2) -- t3, t2, t1
[snippet2-MySQL]select t1.* from stadium t1, stadium t2, stadium t3 where t1.people >= 100 and t2.people >= 100 and t3.people >= 100 and ( (t1.id - t2.id = 1 and t1.id - t3.id = 2 and t2.id - t3.id =1) -- t1, t2, t3 or (t2.id - t1.id = 1 and t2.id - t3.id = 2 and t1.id - t3.id =1) -- t2, t1, t3 or (t3.id - t2.id = 1 and t2.id - t1.id =1 and t3.id - t1.id = 2) -- t3, t2, t1 ) ;
| id | date | people |
|----|------------|--------|
| 7 | 2017-01-07 | 199 |
| 6 | 2017-01-06 | 1455 |
| 8 | 2017-01-08 | 188 |
| 7 | 2017-01-07 | 199 |
| 5 | 2017-01-05 | 145 |
| 6 | 2017-01-06 | 1455 |可以看到查询结果中存在重复的记录，再使用 DISTINCT 去重。
MySQL
[solution1-MySQL]select distinct t1.* from stadium t1, stadium t2, stadium t3 where t1.people >= 100 and t2.people >= 100 and t3.people >= 100 and ( (t1.id - t2.id = 1 and t1.id - t3.id = 2 and t2.id - t3.id =1) -- t1, t2, t3 or (t2.id - t1.id = 1 and t2.id - t3.id = 2 and t1.id - t3.id =1) -- t2, t1, t3 or (t3.id - t2.id = 1 and t2.id - t1.id =1 and t3.id - t1.id = 2) -- t3, t2, t1 ) order by t1.id ;
统计信息
| 通过次数 | 提交次数 | AC比率 |
|---|---|---|
| 33421 | 66295 | 50.4% |
提交历史
| 提交时间 | 提交结果 | 执行时间 | 内存消耗 | 语言 |
|---|
