LeetCode: 197. Rising Temperature

LeetCode: 197. Rising Temperature

题目描述

Given a ​​Weather​​ table, write a SQL query to find all dates’ Ids with higher temperature compared to its previous (yesterday’s) dates.

+---------+------------------+------------------+
| Id(INT) | RecordDate(DATE) | Temperature(INT) |
+---------+------------------+------------------+
|       1 |       2015-01-01 |               10 |
|       2 |       2015-01-02 |               25 |
|       3 |       2015-01-03 |               20 |
|       4 |       2015-01-04 |               30 |
+---------+------------------+------------------+

For example, return the following Ids for the above ​​Weather​​ table:

+----+
| Id |
+----+
|  2 |
|  4 |
+----+

解题思路

The MySQL ​​DATEDIFF​​​ function calculates the number of days between two ​​DATE​​​, ​​DATETIME​​​, or ​​TIMESTAMP​​​values.
The syntax of the MySQL ​​DATEDIFF​​ function is as follows:

DATEDIFF(date_expression_1,date_expression_2);

参考文献：​​MySQL DATEDIFF Function​​

AC 代码

SELECT W1.Id AS Id 
FROM Weather AS w1, Weather AS w2 
WHERE DATEDIFF(w1.RecordDate, w2.RecordDate)=1 AND w1.Temperature > w2.Temperature