Safe SQL in Java CRUD | Dataford Interview Questions

In the code-complete exercise on an existing Java/JDBC CRUD codebase, implement the required database access without introducing SQL injection (parameterized PreparedStatement rather than string formatting).

Asked in the Code complete screen stage. Practical code-complete screen, candidate chose Java.

Write a SQL query that returns active orders for a given customer email domain and minimum order amount.

Output

One row per matching order
Columns: order_id, customer_name, customer_email, order_total, order_status
Include only orders whose status is active, whose total is at least the requested minimum, and whose customer email ends with the requested domain
Ignore rows where customer_email is NULL
Sort by order_total descending, then order_id ascending

Schema

customers

Column	Type	Description
idPK	INT	Primary key for the customer
full_name	VARCHAR(120)	Customer full name
email	VARCHAR(255)	Customer email address
is_active	BOOLEAN	Whether the customer account is active

orders

Column	Type	Description
idPK	INT	Primary key for the order
customer_id	INT	Customer who placed the order
total_amount	NUMERIC(10,2)	Order total amount
status	VARCHAR(20)	Order status
created_at	DATE	Order creation date

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Problem