How to create rails association

Question

How to create rails associations like this:

and example will show like this:

Answer 1

I'd assume you have a users table first, and each User object has_one or has_many skill_set or skill_sets respectively.

Table Name: users
id first_name last_name address 
1  Arslan     Ali       ABC
2  Adnan      Saqib     ABC
3  Mahtab     Maqsood   ABC

And for table, skill_sets:

Table Name: skill_sets
id user_id dance_skill sing_skill model_skill
1  1       1           2          2
2  3       2           2          3
3  2       1           1          2

And, in Rails, you could model it like following:

class User < ActiveRecord::Base
  has_one :skill_set # I'd go with one skill set per user
end

class SkillSet < ActiveRecord::Base
  belongs_to :user # So it'd have 'user_id' in it.
end

For migrations, I'd have something like:

class CreateUsers < ActiveRecord::Migration
  def change
    create_table :users do |t|
      t.stirng first_name
      t.string last_name
      t.string address

      t.timestamps null: false
    end
  end
end

class CreateSkillSets < ActiveRecord::Migration
  def change
    create_table :skill_sets do |t|
      t.references :user, index: true
      t.integer :dance_skill, null: false, default: 1
      t.integer :sing_skill,  null: false, default: 1
      t.integer :model_skill, null: false, default: 1
    end
  end
end

And I don't understand, why are you using the table skills if you all you have do is to store 3 rows. You can have something like the following in your model:

class SkillSet < ActiveRecord::Base
  SKILL_LEVEL = ["Good","Profi","Noob"]      

  def skill_level(number)
    SKILL_LEVEL[number-1] # Arrays are based on zero-index. 
  end

  # Now you can do user.skill_level(user.dance_skill)
  # Other way: You can 'enums' as well, but it is up to you. 
end

Answer 2

You are very close to built the association,and your question is very straightforward. Simply add a field skill_id in model TypeSkill rather skill_model.

And write a simple association into your models

In Skill modle

has_many :type_skills # based on you requirement has_many or has_one

In TypeSkill model

belongs_to :skill