Easy explanation
ExplanationGrouping by sell_dateGROUP BY sell_date ensures we aggregate products per date.
Counting Distinct Products Sold Per DateCOUNT(DISTINCT product) AS nu
# Explanation
Grouping by sell_date

GROUP BY sell_date ensures we aggregate products per date.
Counting Distinct Products Sold Per Date

COUNT(DISTINCT product) AS num_sold counts the unique products sold for each date.
Concatenating Product Names in Lexicographical Order

GROUP_CONCAT(DISTINCT product ORDER BY product SEPARATOR ',') AS products
This ensures the product names are sorted lexicographically and separated by commas.
Ordering Results by Date

ORDER BY sell_date ensures the results are sorted in ascending order of sell_date.

# Code
```mysql []
# 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;

```
['MySQL']