ruby on rails - Virtual columns in a model -

is possible add virtual column model (not virtual attribute!)?

i have following situation: product(id, name) has many productvariant(id, price, offer_price, product_id,...)

when select products want have minimum product price productvariants in products result.

@products = product.with_min_price.order('min_price asc') 

i calculate minimum price in sql query (with_min_price) , want add min_price value each product in @products result.

this method in product class assuming product has_many productvarients

#product model  def min_product_price   product_variants.map(&:price).min end