Group sold products by the date

#
# Table Activities:
# +-------------+---------+
# | Column Name | Type    |
# +-------------+---------+
# | sell_date   | date    |
# | product     | varchar |
# +-------------+---------+
# There is no primary key (column with unique values) for this table. It may contain duplicates.
# Each row of this table contains the product name and the date it was sold in a market.
# Write a solution to find for each date the number of different products sold and their names.
# The sold products names for each date should be sorted lexicographically.
# Return the result table ordered by sell_date.
# The result format is in the following example.
# Example 1:
# Input:
# Activities table:
# +------------+------------+
# | sell_date  | product     |
# +------------+------------+
# | 2020-05-30 | Headphone  |
# | 2020-06-01 | Pencil     |
# | 2020-06-02 | Mask       |
# | 2020-05-30 | Basketball |
# | 2020-06-01 | Bible      |
# | 2020-06-02 | Mask       |
# | 2020-05-30 | T-Shirt    |
# +------------+------------+
# Output:
# +------------+----------+------------------------------+
# | sell_date  | num_sold | products                     |
# +------------+----------+------------------------------+
# | 2020-05-30 | 3        | Basketball,Headphone,T-shirt |
# | 2020-06-01 | 2        | Bible,Pencil                 |
# | 2020-06-02 | 1        | Mask                         |
# +------------+----------+------------------------------+
# Explanation:
# For 2020-05-30, Sold items were (Headphone, Basketball, T-shirt), we sort them lexicographically and separate them by a comma.
# For 2020-06-01, Sold items were (Pencil, Bible), we sort them lexicographically and separate them by a comma.
# For 2020-06-02, the Sold item is (Mask), we just return it.
#

# Write your MySQL query statement below

SELECT sell_date,
  COUNT(DISTINCT product) AS num_sold,
  GROUP_CONCAT(DISTINCT product ORDER BY product SEPARATOR ',') AS products
FROM Activities
GROUP BY sell_date
ORDER BY sell_date;