I am new to ruby-on-rails and have a probably pretty stupid question:

I have a ruby-on-rails-model for a book-list. On the "show"-page I have a button which should take the current id and create a new entry in another table where this id is saved as an integer.

Example:
I am on the page /titles/4 and want a new entry with the value 4 in the title\_id field to be created in the table list.

How is this possible?