Select Count and Quantity

Question

Hello
I have made this query =>
SELECT Products.ProductName, COUNT(*)*OrderDetails.Quantity
FROM Products INNER JOIN OrderDetails ON (Products.ProductID=OrderDetails.ProductID)
GROUP BY Products.ProductName, OrderDetails.Quantity, OrderDetails.OrderID
Well it counts the total from each product but it has also Multiplicate it with the quantity.
My quey is not working because it's shows several time the same product name and the quantity is not correct.
The Group by is not working as it should work. And i think i need to use a SUM() for the quantity.
I'm still new to queries.
Any avice?

Answer 1

Looks like this:
DECLARE @products TABLE (productID INT IDENTITY, productName VARCHAR(30))
DECLARE @orderDetails TABLE (orderID INT, productID INT, quantity INT)
INSERT INTO @products (productName) VALUES
('Orange'),('Apple'),('Inflatable Chicken Suit')
INSERT INTO @orderDetails (orderID, productID, quantity) VALUES
(1,1,1),(1,2,1),(2,3,9),(3,2,16)
SELECT SUM(quantity) AS quantity, p.productID, p.productName
FROM @orderDetails o
INNER JOIN @products p
ON o.productID = p.productID
GROUP BY p.productID, p.productName
You where grouping on too many fields. 
Don't forget to mark helpful posts, and answers. It helps others to find relevant posts to the same question.
Also, when posting questions it helps to provide DDL and example data (as I did at the top of my example).