i need to filter rows and add column value from one table

[akhilpaul]

i have two tables , sales and product details, sales capture data using reference of the product details.   i need to calculate the total qty sold, 

i need to filter the rows in the sales equal to the product name row and add qty column value

[TeeSee1]

In the product table create a virtual column with the following expression

SUM([Related Sales][Quantity Sold])