MySQL
\nselect distinct sell_date, count(distinct product) as num_sold, \ngroup_concat(distinct product order by product) as products\nfrom activities \ngroup by sell
```\nselect distinct sell_date, count(distinct product) as num_sold, \ngroup_concat(distinct product order by product) as products\nfrom activities \ngroup by sell_date\norder by sell_date\n```
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