Question

I’m developing a small application in Ruby-On-Rails. In a controller I have this piece of code:

@user = User.find(current_user.id)
@user.number = current_user.number + 1
@user.save!

Although it locally runs without problems, it crashes on Heroku at line two, with the following error:

NoMethodError (undefined method `+’ for nil:NilClass)

Any tips on how to solve the problem?

Answer 1

If you are storing the number as attribute in your database you should set the default state to 0.

create new migration and regenerate the number column.

def change
  remove_colum :users, :number
  add_column users, :number, :integer, :default => 0

  #ensure that all users with number == nil have got 0 instead nil 
  User.where(:number => nil).update_all(:number => 0)
end