Business Intelligence Path · Mission 4 of 31Starter

Which region should we expand next?

Use LEFT JOIN to include regions with no sales, and handle NULLs with COALESCE

The Brief

Victoria ChenCEOslack-dm

We're evaluating regional expansion for next year. Can you pull a table of all regions with their total revenue and number of sales? I want ALL regions listed even if they haven't had any sales — those gaps are exactly what I'm looking for. Make sure zeros show as 0, not NULL.

You'll practice

LEFT JOINCOALESCENULL handling

Tables & columns available

dim_regionsdim4 columns

Column	Type	Key
region_id	INT	PK
region_name	TEXT
country	TEXT
timezone	TEXT

fact_salesfact8 columns

Column	Type	Key
sale_id	INT	PK
employee_id	INT	FK → dim_employees
product_id	INT	FK → dim_products
region_id	INT	FK → dim_regions
sale_date	TEXT
quantity	INT
revenue	REAL
discount	REAL

Hints (3)

Each hint you reveal reduces the XP you can earn. Try the query first.

Hint 1

Start from dim_regions and LEFT JOIN fact_sales — this keeps all regions even with no matching sales

Hint 2

Use COALESCE(SUM(revenue), 0) so regions with no sales show 0 instead of NULL

Hint 3

GROUP BY region_id and region_name, then ORDER BY total_revenue DESC to surface the biggest opportunities

← Previous

Mission 3

Mission 5

All 31 missions in Business Intelligence Path ↓