SQL Query using string_agg
\nSELECT sell_date, \n    COUNT(product) AS num_sold, \n    STRING_AGG(product,\',\') WITHIN GROUP ( ORDER BY product ASC) AS products\nFROM (SELECT DISTINCT se
```\nSELECT sell_date, \n    COUNT(product) AS num_sold, \n    STRING_AGG(product,\',\') WITHIN GROUP ( ORDER BY product ASC) AS products\nFROM (SELECT DISTINCT sell_date, product FROM Activities)A\nGROUP BY sell_date\n```
['MySQL', 'MS SQL Server']