To select clients from the Customers table who have at least one order in the Orders table, which query will do this correctly? SELECT * FROM Customers WHERE id = (SELECT customer_id FROM Orders); SELECT * FROM Customers c JOIN Orders o ON c.id = o.customer_id; SELECT * FROM Customers, Orders WHERE Customers.id = Orders.id; SELECT * FROM Customers WHERE id IN (SELECT customer_id FROM Orders);

A correct query to list clients from the Customers table who have at least one order in the Orders table is:

SELECT * FROM Customers WHERE id IN (SELECT customer_id FROM Orders);

Explanation:

• The first option with = is not suitable because the subquery returns multiple values, while = expects a single value.
• The second option with JOIN will return clients with orders but may duplicate clients if they have multiple orders.
• The third option with WHERE Customers.id = Orders.id is incorrect because it compares different fields (client id and order id).

Using IN with a subquery is a simple and clear way to get all clients who have orders.