title: association named not found perhaps misspelled issue in rails association
body: <p>Here is my controller</p>
  
  <pre><code>@post = Post.joins(:customers).select("customers.*,posts.*").find params[:id]
  </code></pre>
  
  <p>My post model</p>
  
  <pre><code>belongs_to :customer
  </code></pre>
  
  <p>My customer model</p>
  
  <pre><code>has_many :posts
  </code></pre>
  
  <p>And i am getting error as</p>
  
  <pre><code>Association named 'customers' was not found on Post; perhaps you misspelled it?
  </code></pre>
  
  <p>This is my controller output:</p>
  
  <pre><code>Processing by PostsController#show as */*
    Parameters: {"id"=&gt;"6"}
    Post Load (0.5ms)  SELECT "posts".* FROM "posts" WHERE "posts"."id" = $1 LIMIT 1  [["id", "6"]]
  Completed 500 Internal Server Error in 113ms
  
  ActiveRecord::ConfigurationError (Association named 'customers' was not found on Post; perhaps you misspelled it?):
    app/controllers/posts_controller.rb:16:in `show'
  </code></pre>