SELECT count(*) FROM Products_for_hire WHERE product_id NOT IN ( SELECT product_id FROM products_booked WHERE booked_amount  >  200 )
How many products are never booked with amount higher than 200?
SELECT count ( * ) FROM Products_for_hire WHERE product_id NOT IN ( SELECT product_id FROM products_booked WHERE booked_amount > 200 )
select count ( * ) from products_for_hire where product_id not in ( select product_id from products_booked where booked_amount > value )
How many products are never booked with amount higher than 200 ?