title: Bi-directional one-to-many relationship does not work
body: <p>I have made an application that displays a lot of questions from my database. For this I have made a question entity. I want to be able to "report" a question for being poor/good and so on, so for this I made a feedback entity. </p>
  
  <p>The relationship between these would be: one question may have many feedbacks, and one feedback belongs to one question.</p>
  
  <p>The problem is that when I save the question feedback instance it all maps perfectly in the database, but when I open a question and loops through all the feedbacks none of the feedbacks added is displayed. In order to have them displayed I need to re-deploy the web application. </p>
  
  <p>Why does this happen? </p>
  
  <p><strong>For readability I only show the parts involved</strong></p>
  
  <p><strong>QuestionFeedback entity</strong></p>
  
  <pre><code>public class QuestionFeedback implements Serializable {
  
      @ManyToOne
      private Question question;
      ....
  
      public void setQuestion(Question question) {
          this.question = question;
  
          if (!question.getFeedbacks().contains(this)) {
              question.getFeedbacks().add(this);
          }
      }
      ....
  }
  </code></pre>
  
  <p><strong>Question entity</strong></p>
  
  <pre><code>@Entity
  public class Question implements Serializable {
  
      @OneToMany(mappedBy = "question", fetch = FetchType.EAGER)
      private List&lt;QuestionFeedback&gt; feedbacks;
  
      public Question() {
          feedbacks = new ArrayList&lt;QuestionFeedback&gt;();
      }
  
      public void addFeedback(QuestionFeedback questionFeedback) {
  
          if (!getFeedbacks().contains(questionFeedback)) {
              getFeedbacks().add(questionFeedback);
          }
  
          if (questionFeedback.getQuestion() != this) {
              questionFeedback.setQuestion(this);
          }
      }
  }
  </code></pre>
  
  <p><strong>Backing bean for the report page</strong></p>
  
  <p>The question entity is already retrieved from the database.</p>
  
  <pre><code>public String flag() {
      questionFeedback.setQuestion(question);
      questionFeedbackService.persist(questionFeedback);
  
      return "index";
  }
  </code></pre>
  
  <p><strong>DAO class</strong></p>
  
  <pre><code>public void persist(QuestionFeedback questionFeedback) {
      entityManager.persist(questionFeedback);
  }
  </code></pre>