sql very easy solution
\nselect sell_date,\ncount(distinct(product)) num_sold,\ngroup_concat(distinct(product)) products\nfrom Activities\ngroup by sell_date\norder by sell_date;
```\nselect sell_date,\ncount(distinct(product)) num_sold,\ngroup_concat(distinct(product)) products\nfrom Activities\ngroup by sell_date\norder by sell_date;```
['MySQL']