Show all product names and the number of customers having an order on each product.
select t2.product_name, count ( * ) from order_items as t1 join products as t2 on t1.product_id = t2.product_id join orders as t3 on t3.order_id = t1.order_id group by t2.product_name
Please show me unit price of books?
select unit_price from products where production_type_code = "Books"
Please give me Placed order date of customer id 12?
select date_order_placed from orders where customer_id = 12