1251-average-selling-price.sql

# Write your MySQL query statement below
SELECT a.product_id,ROUND(SUM(b.units*a.price)/SUM(b.units),2) as average_price
FROM Prices as a
JOIN UnitsSold as b
ON a.product_id=b.product_id AND (b.purchase_date BETWEEN a.start_date AND a.end_date)
GROUP BY product_id;