How to get an array from multiple select collections?

Question

Ruby on Rails

users = Users.all(some more conditional)
The user does not have includes comments
In the view I have a search and user.its_a_magic method where Comment.where(user_id: user.id)
I was offered to select all "comments" and form an array user_id => comment in the controller
And write the method find_comment_by_user
User.includes(:comments).select('users.id, comments.*')
So I will get an array of thoughtsal me and it remains to parse it properly, but no.
It output only user