Your question is Multiple Orders With NULL Handling. Start with the requirements and the two tables on the right.
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Write a SQL query to identify customers who ordered more than once and handle NULL values in orders.
Use the customers and orders tables. Treat NULL order amounts as zero, exclude orders with NULL customer IDs, and display Unknown when a customer's name is NULL.
customer_id, customer_name, order_count, and total_order_value.customer_id in ascending order.| Column | Type | Description |
|---|---|---|
| customer_idPK | INTEGER | Unique customer identifier |
| customer_name | VARCHAR(100) | Customer's display name |
| Column | Type | Description |
|---|---|---|
| order_idPK | INTEGER | Unique order identifier |
| customer_id | INTEGER | Customer who placed the order |
| order_amount | NUMERIC(10,2) | Monetary value of the order |
| order_date | DATE | Date the order was placed |