like i have 1000 order entry in each entry i have multiple products with sold quantity for top selling products.heaare my challange is i need return the top sold products example:
order entry  : product id  :sold quantity;;;;
entry 1     : productA    :20 
            :productB     :10
             :productC     :5
entry 2      :productB     :5
             :productc      :20
how can get the top selling product.