List down the first name of customers who placed order for product id 1.
SELECT T1.FirstName FROM Customers AS T1 INNER JOIN Sales AS T2 ON T1.CustomerID = T2.CustomerID INNER JOIN Products AS T3 ON T2.ProductID = T3.ProductID WHERE T2.ProductID = 1
database name:db_id sales
Customers table Customers Cols: Customer ID dtype integer, First Name dtype text, Middle Initial dtype text, Last Name dtype text, 
Employees table Employees Cols: Employee ID dtype integer, First Name dtype text, Middle Initial dtype text, Last Name dtype text, 
Products table Products Cols: Product ID dtype integer, Name dtype text, Price dtype real, 
Sales table Sales Cols: Sales ID dtype integer, SalesPerson ID dtype integer, Customer ID dtype integer, Product ID dtype integer, Quantity dtype integer, 
