I\'m getting an error:
SQLite3::SQLException: no such column: ideas.list_id: SELECT \"ideas\".* FROM \"ideas\" WHERE \"ideas\".\"list_id\" = 2
If you want to add a new column to an exist database, you should use rails generate migration. So you can try rails generate migration add_list_id_to_ideas list_id:integer and then use rake db:migrate to commit this change.
rails generate migration
rails generate migration add_list_id_to_ideas list_id:integer
rake db:migrate