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My solution aims to achieve the following tasks:\n\n1. Group by sell_date to get counts and concatenations of products sold on each date.\n2. Count distinct pro
My solution aims to achieve the following tasks:\n\n1. **Group by `sell_date`** to get counts and concatenations of products sold on each date.\n2. **Count distinct products** sold on each date.\n3. **Concatenate distinct product names** in ascending order, separated by commas.\n\nHere\'s a breakdown of the components and the complexities involved:\n\n## Intuition\nYou need to gather information about sales activities, specifically counting distinct products sold on each date and listing those products in a sorted, comma-separated string. This involves aggregating data by date and performing operations on grouped data.\n\n## Approach\n1. **Group By `sell_date`**: This ensures you perform operations on each date\'s sales activities separately.\n2. **Count Distinct Products**: Use `COUNT(DISTINCT product)` to get the number of unique products sold each day.\n3. **Concatenate Products**: Use `GROUP_CONCAT` to concatenate distinct product names, ordering them alphabetically.\n\n## Complexity\n### Time Complexity\n- **Grouping and Counting**: Grouping the data by `sell_date` and counting distinct products involves scanning through all records, which is \\(O(n)\\), where \\(n\\) is the number of rows in the `Activities` table.\n- **Concatenation and Sorting**: Concatenating and sorting products for each group is dependent on the number of distinct products per date. If \\(m\\) is the number of distinct products per date, the complexity for sorting and concatenation is \\(O(m \\log m)\\).\n\nOverall, the time complexity is \\(O(n + k \\cdot m \\log m)\\), where \\(k\\) is the number of distinct dates and \\(m\\) is the average number of distinct products per date.\n\n### Space Complexity\n- **Storage for Grouped Data**: Requires space for storing grouped results. If there are \\(k\\) distinct dates and each date has \\(m\\) distinct products on average, the space complexity is \\(O(k \\cdot m)\\).\n- **Intermediate Storage**: Space for intermediate results during concatenation and sorting, which is also \\(O(k \\cdot m)\\).\n\nOverall, the space complexity is \\(O(k \\cdot m)\\).\n\n## Code\n```sql\n-- Write your MySQL query statement below\nSELECT sell_date, \n       COUNT(DISTINCT product) AS num_sold,\n       GROUP_CONCAT(DISTINCT product ORDER BY product ASC SEPARATOR \',\') AS products\nFROM Activities \nGROUP BY sell_date \nORDER BY sell_date ASC;\n```\n\nThis query:\n1. Selects the `sell_date`.\n2. Counts the number of distinct `product` entries for each `sell_date`.\n3. Concatenates the distinct `product` entries in ascending order, separated by commas.\n4. Groups the results by `sell_date` and sorts the results in ascending order by `sell_date`.\n\nThis approach ensures efficient querying and clear results presentation for the sales activities on different dates.
['MySQL']