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POBi-directional one-to-many relationship does not work
 

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  1. POBi-directional one-to-many relationship does not work
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    <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>
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    1. USLuckyLuke
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      1. USDead Programmer
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    1. COIf I correctly understand your question, this seems to be a transactional problem as data is correctly stored in the database, correct? If true, it must relate to your entity manager usage (and configuration)...
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      1. UShome
    2. COThat is probably true yes. If I refresh the question entity in the find method of my DAO, it works. Seems like it caches it or something. I am using Glassfish with container-managed transactions.
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      1. USLuckyLuke
 

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