197. Rising Temperature
Giới thiệu bài toán
Chi tiết: https://leetcode.com/problems/rising-temperature/
Table: Weather
| Column Name | Type |
|---|---|
| id | int |
| recordDate | date |
| temperature | int |
- In SQL, id is the primary key for this table.
- This table contains information about the temperature on a certain day.
Yêu cầu
Find all dates' Id with higher temperatures compared to its previous dates (yesterday).
Return the result table in any order. The result format is in the following example.
Example 1:
Input: Weather table:
| id | recordDate | temperature |
|---|---|---|
| 1 | 2015-01-01 | 10 |
| 2 | 2015-01-02 | 25 |
| 3 | 2015-01-03 | 20 |
| 4 | 2015-01-04 | 30 |
Output:
| id |
|---|
| 2 |
| 4 |
- Explanation:
- In 2015-01-02, the temperature was higher than the previous day (10 -> 25).
- In 2015-01-04, the temperature was higher than the previous day (20 -> 30).
Giải quyết bài toán
SELECT w1.id
FROM Weather w1 JOIN Weather w2
ON w1.RecordDate = DATE_ADD(w2.RecordDate, INTERVAL 1 DAY)
WHERE w1.temperature > w2.temperature;
Tham khảo: https://leetcode.com/submissions/detail/1039224990/