SQL With Table Schema | Dataford Interview Questions

Given a schema of three tables, write the SQL needed to answer a business question.

Use the supplied schema to return customers who placed at least two completed orders during the first quarter of 2025. Calculate their total item revenue from those orders and sort the results by revenue.

Output

One row per qualifying customer.
Columns: customer_name, completed_order_count, and total_revenue.
Include only completed orders dated from 2025-01-01 through 2025-03-31.
Sort by total_revenue descending, then customer_name ascending to break ties.

Schema

customers

Column	Type	Description
customer_idPK	INT	Unique customer identifier
customer_name	VARCHAR(100)	Customer display name
email	VARCHAR(255)	Customer email address

orders

Column	Type	Description
order_idPK	INT	Unique order identifier
customer_id	INT	Customer who placed the order
order_date	DATE	Date the order was placed
status	VARCHAR(20)	Order lifecycle status
shipped_at	DATE	Date the order shipped

order_items

Column	Type	Description
order_item_idPK	INT	Unique order item identifier
order_id	INT	Order containing the item
item_description	VARCHAR(150)	Description of the purchased item
quantity	INT	Number of units purchased
unit_price	DECIMAL(10,2)	Price per unit

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Problem