DateBase -- Rising Temperature

Posted 2020-06-18 江湖小妞

Question:

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) | Date(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 |
+----+

 

Analysis：

给出一张温度表格，写一个SQL语句找出所有的温度比前一天温度高的日期id。

数据库的题目，常年不用都忘了。跑去官网查文档，一点点拾起来吧~

 

Answer：

select w1.id from Weather w1, Weather w2 where w1.Temperature > w2.Temperature and DATEDIFF(w1.Date, w2.Date) = 1;