app/models/skill.rb
class Skill < ActiveRecord::Base
validates_presence_of :name
validates_uniqueness_of :name, case_sensitive: false
validates_presence_of :description
has_many :job_skills
has_many :jobs, through: :job_skills, dependent: :destroy
belongs_to :organization, polymorphic: true
def has_job?
jobs.any?
end
end