faster than 83% of MySQL online submissions
<<<<upvote \n\n\tSELECT sell_date, COUNT( DISTINCT product ) AS num_sold ,    \n    GROUP_CONCAT( DISTINCT product ORDER BY product ASC separator \',\' ) AS pro
**<<<<upvote **\n\n\tSELECT sell_date, COUNT( DISTINCT product ) AS num_sold ,    \n    GROUP_CONCAT( DISTINCT product ORDER BY product ASC separator \',\' ) AS product   \n    FROM Activities GROUP BY sell_date ORDER BY sell_date ASC;
['MySQL']