rails generate migration add_index_to... does not put the actual index in the migration file

Question

I created a users table via "rails generate model User name:string email:string ..." the migration file was created as well.

class CreateUsers < ActiveRecord::Migration   def change     create_table :users do |t|       t.string :name       t.string :email        t.timestamps     end   end end 

Now I want to add an index to the email column "following the tutorial" I've done this successfully the first time through using sqlite3. Second time through im using MySql (mysql2). Again created the table fine with generate model.. When I run the following:

rails generate migration add_index_to_users_email 

the process ends with no error message and creates the migration file as shown below, but there is no setting of any index..

class AddIndexToUsersEmail < ActiveRecord::Migration   def change   end end 

Im expecting to see add_index :users, :email, unique: true in there ... Anybody have any idea's.. searched other threads to no avail.. running rails 4, mysql 5.6 ruby 1.9.3 my schema that was created after initil db:migrate is:

ActiveRecord::Schema.define(version: 20131024161033) do    create_table "users", force: true do |t|     t.string   "name"     t.string   "email"     t.string   "city"     t.string   "state"     t.string   "zip"     t.string   "mobile_phone"     t.string   "mobile_phone_type"     t.date     "birth_date"     t.string   "user_type"     t.string   "ss_num"     t.boolean  "agree_to_terms"     t.datetime "created_at"     t.datetime "updated_at"   end  end 

Answer 1

via http://guides.rubyonrails.org/migrations.html

If you'd like to add an index on the new column, you can do that as well:

$ rails generate migration AddPartNumberToProducts part_number:string:index

your generator

rails generate migration add_index_to_users_email 

simply creates an empty migration file and did not describe a index

so this would be more appropriate...

rails generate migration AddIndexToUsers email:string:index 

should give you

class AddIndexToUsers < ActiveRecord::Migration   def change     add_index :users, :email   end end 

---

Nguyen You - EDIT

This command [Rails 5.2.3]

rails generate migration AddIndexToUsers email:string:index 

actually will give you

class AddIndexToUsers < ActiveRecord::Migration[5.2]   def change     add_column :users, :email, :string     add_index :users, :email   end end 

not only add_index but also add_column to the users table.