Window Functions for Top Items

Write a query using window functions to find the top three most-ordered food items for each city on a monthly basis.

Use completed orders only and treat ordered quantity as the ranking measure. Return only the top three items per city and month.

Output

1. One row per city, month, and qualifying food item.
2. Columns: city, month, food_item, total_quantity, and item_rank.
3. Order by city, month, item_rank, then food_item.

Output details

• Format month as YYYY-MM.
• Rank items by total_quantity descending.
• Break equal quantities by food_item ascending.
• Assign unique ranks and retain exactly three items per city and month.
• Sort city, month, item_rank, and food_item in ascending order.