Does rails have any way to have complex sorting at the database query level?
Ie/
Posts.order(up / down).all ?
What would be the best way to implement this on a database level (in postgres) without having to sort through a result in ruby using sort (which will slow down pagination etc).
If you use the wonderful meta_where gem, you can also do something like
Post.order(:create_at.asc)
To sort by a function of two or more columns you can do something like
Post.select("*, (up / down) as ratio").order("ratio asc")
You will have what you want and moreover every Post object in that array will have a ratio method for you to know the exact value.
Post.order("created_at DESC").all
Post.order("title ASC").all
See here, for more details.
Post.select("*, (up / greatest(down, 1)) as ratio").order("ratio asc")
