Write a SQL query to analyze weekly store sales by region, compare them to the prior week, and identify stores with declining performance.
Use the provided store, region, and weekly sales data. Compare only consecutive calendar weeks where prior-week data exists.
Output
- One row per store-week with declining sales.
- Columns:
region_name, store_id, store_name, week_start, weekly_sales, prior_week_sales, sales_change, region_weekly_sales, region_prior_week_sales.
- Order by
region_name, week_start, and store_id.
