Table: Sales
+---------------+---------+ | Column Name | Type | +---------------+---------+ | sale_date | date | | fruit | enum | | sold_num | int | +---------------+---------+ (sale_date, fruit) is the primary key for this table. This table contains the sales of "apples" and "oranges" sold each day.
Write an SQL query to report the difference between the number of apples and oranges sold each day.
Return the result table ordered by sale_date.
The query result format is in the following example.
Example 1:
Input: Sales table: +------------+------------+-------------+ | sale_date | fruit | sold_num | +------------+------------+-------------+ | 2020-05-01 | apples | 10 | | 2020-05-01 | oranges | 8 | | 2020-05-02 | apples | 15 | | 2020-05-02 | oranges | 15 | | 2020-05-03 | apples | 20 | | 2020-05-03 | oranges | 0 | | 2020-05-04 | apples | 15 | | 2020-05-04 | oranges | 16 | +------------+------------+-------------+ Output: +------------+--------------+ | sale_date | diff | +------------+--------------+ | 2020-05-01 | 2 | | 2020-05-02 | 0 | | 2020-05-03 | 20 | | 2020-05-04 | -1 | +------------+--------------+ Explanation: Day 2020-05-01, 10 apples and 8 oranges were sold (Difference 10 - 8 = 2). Day 2020-05-02, 15 apples and 15 oranges were sold (Difference 15 - 15 = 0). Day 2020-05-03, 20 apples and 0 oranges were sold (Difference 20 - 0 = 20). Day 2020-05-04, 15 apples and 16 oranges were sold (Difference 15 - 16 = -1).
# Write your MySQL query statement below
SELECT
sale_date AS SALE_DATE,
sum(
CASE WHEN fruit = 'oranges' THEN -sold_num ELSE sold_num END
) AS DIFF
FROM
Sales
GROUP BY sale_date
ORDER BY sale_date;