migrate file exists but no model for rails application - ruby-on-rails

Question

migrate file exists but no model for rails application.There are user and book model.I created join table between user and book model.
I write console : rails g migration CreateJoinTableBooksUsers books users
rake:db migrate
**schema.rb**
create_table "books", force: :cascade do |t|
t.string "title"
t.string "author"
t.integer "page_count"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
t.boolean "status"
t.string "user_id"
t.boolean "barter_status"
end
create_table "books_users", id: false, force: :cascade do |t|
t.bigint "book_id", null: false
t.bigint "user_id", null: false
end
create_table "users", force: :cascade do |t|
t.string "email", default: "", null: false
t.string "encrypted_password", default: "", null: false
t.string "reset_password_token"
t.datetime "reset_password_sent_at"
t.datetime "remember_created_at"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
t.string "username"
t.index ["email"], name: "index_users_on_email", unique: true
t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
t.index ["username"], name: "index_users_on_username", unique: true
end
add_foreign_key "comments", "books"
add_foreign_key "comments", "users"
end
**migrate**
class CreateJoinTableBooksUsers < ActiveRecord::Migration[6.0]
def change
create_join_table :books, :users do |t|
t.index [:book_id, :user_id]
t.index [:user_id, :book_id]
end
end
end

Answer 1

A migration creates the tables in the database but doesn't create anything else.
But, for a true join table, you don't need a model:
https://guides.rubyonrails.org/association_basics.html#the-has-and-belongs-to-many-association
# app/models/user.rb
class User < ApplicationRecord
has_and_belongs_to_many :books
end
# app/models/books.rb
class Book < ApplicationRecord
has_and_belongs_to_many :users
end
IF you need scopes, callbacks, or methods on BooksUsers, you can use the has_many :through option:
https://guides.rubyonrails.org/association_basics.html#choosing-between-has-many-through-and-has-and-belongs-to-many
# app/models/user.rb
class User < ApplicationRecord
has_many :books_users
has_many :books, through: :books_users
end
# app/models/books.rb
class Book < ApplicationRecord
has_many :books_users
has_many :users, through: :books_users
end
In this case, you'll need to generate a model:
rails generate model BooksUsers