Question

I’m using Ruby on Rails 2.3.8 and I would like to get all the @products that haven’t been already added to the listed_products array.

For example, let’s say I’ve got the following code:

listed_products = ['1', '2', '3', '4', '5']

#Then, I would like to do something like SELECT * FROM products where id not in
#(listed_products), and save the result in @products

I know the above SQL syntax won’t work, but I just wanted to give you guys the idea of what I want to achieve.

Is there a “rails way” for doing this?

Thanks in advance!

Answer 1

Yes, you can do the following (Rails 2.3.x):

listed_products = [1,2,3,4,5]
Product.find(:all, :conditions => ["id NOT IN (?)", listed_products])

Or this in Rails 3.0.x:

listed_products = [1,2,3,4,5]
Product.where("id NOT IN (?)", listed_products)