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Inactive Customers by Tier
Which membership tier has the highest share of inactive customers (zero orders)? For each membership, show total_customers, inactive_customers (customers whose order_count is 0), and inactive_pct (rounded to 1 decimal, as a percentage of total_customers in that tier). Sort by inactive_pct descending. This is a classic LEFT JOIN + conditional aggregation pipeline: first get order counts per customer, then roll up by tier.
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Schema
customers
| customer_id | name | signup_date | membership | total_orders | |
|---|---|---|---|---|---|
| 1 | John Smith | john.smith@email.com | 2023-01-15 | Gold | 15 |
| 2 | Emma Wilson | emma.wilson@email.com | 2023-03-20 | Silver | 8 |
| 3 | Michael Brown | michael.brown@email.com | 2023-02-10 | Gold | 12 |
orders
| order_id | customer_id | product | category | quantity | price | total | order_date | country | status |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | Laptop Pro | Electronics | 1 | 1299.99 | 1299.99 | 2024-01-15 | USA | completed |
| 2 | 2 | Wireless Mouse | Electronics | 2 | 49.99 | 99.98 | 2024-01-16 | Canada | completed |
| 3 | 3 | Office Chair | Furniture | 1 | 349.99 | 349.99 | 2024-01-17 | USA | completed |
Expected output: Silver | 10 | 3 | 30.0
Hint
Concepts
SELECT LEFT JOIN CASE GROUP BY Derived Table LEFT JOIN + CASE
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