代码改变世界

[LeetCode] 197. Rising Temperature_Easy tag: SQL

2018-08-18 05:54  Johnson_强生仔仔  阅读(217)  评论(0编辑  收藏  举报

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 |
+----+

Code

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

or

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