Question

I have a user model that has an associated cart. Each cart has a purchased_at datetime column.
I want to select all users that have have not purchased a cart in the last 3 months.

I though a simple:

User.joins(:carts).where('not carts.purchased_at < ?', 3.months.ago)

would do the trick but this doesn’t seem to be the case. I’m being returned user records who have purchased something in the past 3 months.

Any thoughts?

Answer 1

You should be able to do this is in plain active record:

User.joins(:carts)
  .group("users.id")
  .having("MAX(carts.purchased_at) < ?", 3.months.ago)