How to store product quantity in database
<p>I have database with three tables</p>

<pre><code>product         (productID,productName,productDescription) 
size            (sizeID , sizeName) eg. s ,m ,l ,8,10,12,37,35..etc 
ProductDetails  (ProductDetailsID, productID(FK) , sizeID (FK))
</code></pre>

<p>I want to store the quantity of each product and it size for example there are 5 in stock for product 1 of size s, 10 in stock for product 4 size 37 ..etc </p>

<p>In which table should I place the quantity ?</p>