WARNING: Can't mass-assign protected attributes

Question

I get this error \"WARNING: Can\'t mass-assign protected attributes: races_attributes\" , when following this http://railscasts.com/episodes/196-nested-model-form-part-1 on rail

Answer 1

attr_accessible specifies that you can not mass-assign attributes, using save method, for example. So, if you change an attribute that is not defined with attr_accessible, you will get a warning because it will not actually be saved in the database.