INSERT INTO sales (Product_idProduct, sale_date, price, [count])
SELECT TOP(100) (RAND(id) * 3) + 1,
DATEADD(dd, - (1000 * RAND(id)), GETDATE()),
(RAND(id) * 100) + 1, (RAND(id) * 10) + 1
FROM sysobjects
ORDER BY id DESC