Part 55: Multi-Column Grouping & Aggregation Hierarchies

Grouping by multiple columns produces breakdown reports across subcategories.

1. Syntax

SELECT 
  country,
  city,
  COUNT(*) AS store_count,
  SUM(total_sales) AS total_revenue
FROM stores
GROUP BY country, city
ORDER BY country, total_revenue DESC;

Key Takeaways

• Grouping across multiple columns reveals multi-dimensional data breakdowns.

In Part 56, we will explore Advanced Grouping: GROUPING SETS for Flexible Reporting!