Difficulty: Hard
X city built a new stadium, each day many people visit it and the stats are saved as these columns: id, date, people
Please write a query to display the records which have 3 or more consecutive rows and the amount of people more than 100(inclusive).
For example, the table stadium:
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| +------+------------+-----------+
| id | 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 | 2017-01-08 | 188 |
+------+------------+-----------+
|
For the sample data above, the output is:
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| +------+------------+-----------+
| id | date | people |
+------+------------+-----------+
| 5 | 2017-01-05 | 145 |
| 6 | 2017-01-06 | 1455 |
| 7 | 2017-01-07 | 199 |
| 8 | 2017-01-08 | 188 |
+------+------------+-----------+
|
Note:
Each day only have one row record, and the dates are increasing with id increasing.
Solution
Language: MySQL
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| # Write your MySQL query statement below
select distinct s1.*
from stadium s1, stadium s2, stadium s3
where s1.people >= 100 and
s2.people >= 100 and
s3.people >= 100 and
(
(s1.id + 1 = s2.id and s1.id + 2 = s3.id) or
(s1.id - 1 = s2.id and s1.id + 1 = s3.id) or
(s1.id - 2 = s2.id and s1.id - 1 = s3.id)
)
order by s1.id asc;
|