Uninitialized constant Rails 4

Question

Basically I'm using many-to-many relationship with through to combine Skill and Course models. So it looks like this:

Course

has_many :course_skills
has_many :skills, through: :course_skills

Skill

has_many :course_skills
has_many :courses, through: :course_skills

CourseSkills

belongs_to :skill
belongs_to :course

And I'd like to be able to add many skills to courses so the view looks like this:

  <div class="field">
    <%= f.label :skill, "Skills" %>
    <%= f.collection_check_boxes :skill_ids, Skill.all, :id, :title %>
  </div>

When I didn't have this setup, but only used belongs_to and has_many it worked, but now I'm getting an error that says: uninitialized constant Course::CourseSkill and points me to the line where the collection_check_boxes are. So what am I doing wrong? Also I was folloing this previous post if that makes my point more clear: How to add multiple many-to-many fields in one form with Rails 4?

Answer 1

As OP agreed in the comment, with my suggestion in the comment , I am taking it into the answer -

Your model name should be CourseSkill , not CourseSkills . As per the Rails convention has_many :course_skills , translated to the model name as CourseSkill ..Look the doc The name of the other model is pluralized when declaring a has_many association. . Now read it reverse way..