Problem

Table: Weather

+---------------+---------+
| Column Name   | Type    |
+---------------+---------+
| id            | int     |
| recordDate    | date    |
| temperature   | int     |
+---------------+---------+
id is the primary key for this table.
This table contains information about the temperature on a certain day.

Write an SQL query to find all dates’ Id with higher temperatures compared to its previous dates (yesterday).

Return the result table in any order.

The query result format is in the following example.

Examples

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).

Solution

Method 1 - Using where clause

Code

SQL
SELECT q.id AS id FROM Weather p
JOIN Weather q
WHERE q.recordDate = (p.recordDate + 1) AND q.temperature > p.temperature

But above will not work, as we are not using date addition operator correctly. We can do:

SELECT q.id AS id FROM Weather p
JOIN Weather q
WHERE TO_DAYS(q.recordDate) = TO_DAYS(p.recordDate) + 1 AND q.temperature > p.temperature