railsで検索機能をつけたい

ruby on railsを用いて、投稿した本や投稿したユーザーの名前を検索する機能をつくりたいです。
ユーザーの名前検索は機能するのですが、本の名前検索では写真のようなエラーがでました。
searchメソッドは定義したつもりですが、メソッドのエラーがでました。
プログラミング初心者で、このエラーの原因がわかりません。ご指導お願いいたします。

book.rb

class Book < ApplicationRecord
  
  belongs_to :user
  has_many :book_comments, dependent: :destroy
  has_many :favorites, dependent: :destroy

  def favorited_by?(user)
    favorites.where(user_id: user.id).exists?
  end
  
  validates :title, presence: true
  validates :body, presence: true,length: { maximum: 200 }
  
  def self.looks(word, search)
    if search == "perfect_match"
      Book.where("title LIKE?", "#{word}")
    elsif search == "forward_match"
      Book.where("title LIKE?", "#{word}%")
    elsif search == "backword_match"
      Book.where("title LIKE?", "%#{word}")
    elsif search == "partial_match"
      Book.where("title LIKE?", "%#{word}%")
    else
      Book.all
    end
  end
  
  
end

user.rb

class User < ApplicationRecord
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable, :trackable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :validatable
  
   has_many :books, dependent: :destroy
   has_many :book_comments, dependent: :destroy
   has_many :favorites, dependent: :destroy
   attachment :profile_image
   
   has_many :reverse_of_relationships, class_name: "Relationship", foreign_key: "followed_id", dependent: :destroy
   has_many :followers, through: :reverse_of_relationships, source: :follower
   has_many :relationships, class_name: "Relationship", foreign_key: "follower_id", dependent: :destroy
   has_many :followings, through: :relationships, source: :followed
   
   
  validates :name,length: { minimum: 2, maximum: 20 } ,uniqueness: true
  validates :introduction,length: { maximum: 50 }
  
  def follow(user_id)
    relationships.create(followed_id: user_id)
  end
  def unfollow(user_id)
    relationships.find_by(followed_id: user_id).destroy
  end
  def following?(user)
    followings.include?(user)
  end
  
    def self.search(search, word)
      if search == "forward_match"
        @user = User.where("name LIKE?", "#{word}%")
      elsif search == "backward_match"
        @user = User.where("name LIKE?", "%#{word}")
      elsif search == "perfect_match"
        @user = User.where("#{word}")
      elsif search == "partial_match"
        @user = User.where("name LIKE?", "%#{word}%")
      else
        @user = User.all
      end
    end

  
end

search.html.erb

<h2>Books search for '<%= params[:word] %>'</h2>
<!--books一覧 -->
<table class="table table-hover table-inverse">
　<% if @range == '2' %>
  <thead>
    <tr>
     <th></th>
     <th>Title</th>
     <th>Opinion</th>
     <th colspan="3"></th>
    </tr>
  </thead>


  <tbody>
     <% @book.each do |book| %>
     <tr>
      <td>
       <%= link_to(book.user) do %>
       <% end %>
      </td>
      <td>
       <%= link_to book.title, book, class: "book_#{book.id}" %>
      </td>
      <td><%= book.body %></td>
     </tr>
     <% end %>
  </tbody>

  <% else %>
  <thead>
     <tr>
      <th>image</th>
      <th>name</th>
      <th colspan="3"></th>
     </tr>
   </thead>

   <tbody>
    <% @user.each do |user| %>
     <tr>
      <td><%= user.name%></td>
      <td><%= link_to "Show", user, class: "user_#{user.id}" %></td>
     </tr>
    <% end %>
   </tbody>
   <% end %>
 </table>

searches_controller.rb


class SearchesController < ApplicationController

  before_action :authenticate_user!

  def search
    @range = params[:range]
    search = params[:search]
    word = params[:word]

    if @range == '1'
      @user = User.search(search, word)
    else
      @book = Book.search(search, word)
    end
  end
end

application.html.erb


<!DOCTYPE html>
<html>
  <head>
    <title>Bookers2</title>
    <%= csrf_meta_tags %>
    <%= csp_meta_tag %>
    <meta name="viewport" content="width=device-width,initial-scale=1">

    <%= stylesheet_link_tag    'application', media: 'all', 'data-turbolinks-track': 'reload' %>
    <%= javascript_include_tag 'application', 'data-turbolinks-track': 'reload' %>
  </head>

  <body>
    <header>
      <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
        <div class="container">
          <a class="navbar-brand" href="/"><span>Bookers</span></a>
          <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNavDropdown" aria-controls="navbarNavDropdown" aria-expanded="false" aria-label="Toggle navigation">
            <span class="navbar-toggler-icon"></span>
          </button>
          <div class="collapse navbar-collapse" id="navbarNavDropdown">
            <ul class="navbar-nav ml-auto">
              <% if user_signed_in? %>
                <li>
                  <%= link_to user_path(current_user) do %>
                    <i class="fas fa-home nav-link text-light"> Home</i>
                  <% end %>
                </li>
                <li>
                  <%= link_to users_path do %>
                    <i class="fas fa-users nav-link text-light"> Users</i>
                  <% end %>
                </li>
                <li>
                  <%= link_to books_path do %>
                    <i class="fas fa-book-open nav-link text-light"> Books</i>
                  <% end %>
                </li>
                <li>
                  <%= link_to destroy_user_session_path, method: :delete  do %>
                    <i class="fas fa-sign-out-alt nav-link text-light"> logout</i>
                  <% end %>
                </li>
              <% else %>
                <li>
                  <%= link_to root_path do %>
                    <i class="fas fa-home nav-link text-light"> Home</i>
                  <% end %>
                </li>
                <li>
                  <%= link_to home_about_path do %>
                    <i class="fas fa-link nav-link text-light"> About</i>
                  <% end %>
                </li>
                <li>
                  <%= link_to new_user_registration_path do %>
                    <i class="fas fa-user-plus nav-link text-light"> sign up</i>
                  <% end %>
                </li>
                <li>
                  <%= link_to  new_user_session_path do %>
                    <i class="fas fa-sign-in-alt nav-link text-light"> login</i>
                  <% end %>
                </li>
              <% end %>
            </ul>
          </div>
        </div>
      </nav>
    </header>
    
    <% if flash[:notice] %>
      <p id="notice"><%= flash[:notice] %></p>
    <% end %>
    
        <% if user_signed_in? %>
           <%= form_tag(search_path, method: :get) do %>
            <%= text_field_tag (:word) %>
            <%= select_tag 'range', options_for_select([["User", "1"], ["Book", "2"]]) %>
              <%= select_tag 'search', options_for_select([["前方一致","forward_match"], ["後方一致", "backward_match"],["完全一致", "parfect_match"], ["部分一致", "partial_match"]]) %>
            <%= submit_tag :search %>
          <% end %>
        <% end %>
    
    
    
    <%= yield %>
    
    <footer>
      <div class="container mt-5">
        <div class="row">
          <div class ="mx-auto">CopyRight Infratop.inc</div>
        </div>
      </div>
    </footer>
  </body>
</html>

routes.rb


Rails.application.routes.draw do

  devise_for :users
  root to: 'homes#top'
  get 'search' => 'searches#search'
  get "home/about" => "homes#about" 
  resources :books, only: [:edit, :create, :index, :show, :destroy, :update] do
    resource :favorites, only: [:create, :destroy]
    resources :book_comments, only: [:create, :destroy]
  end
  resources :users, only: [:show, :edit, :update, :index] do
    resource :relationships, only: [:create, :destroy]
    get 'followings' => 'relationships#followings', as: 'followings'
    get 'followers' => 'relationships#followers', as: 'followers'
  end
end