java 如何在 Hibernate 中更新集合？

How do I update a Collection in Hibernate?

提问by J Ellis

I have an object called "Document" that has a one-to-many relationship with "DocumentPersonCc". I am trying to change one or more of these collections in my code, but Hibernate is not calling the update query when I expect it. It does call the update query when I change one of the regular fields (like the document subject), but even then it does not persist any of the one-to-many changes within the database. What do I need to change in order to get it to work?

我有一个名为“Document”的对象，它与“DocumentPersonCc”是一对多的关系。我试图在我的代码中更改这些集合中的一个或多个，但是 Hibernate 没有在我期望的时候调用更新查询。当我更改常规字段之一（如文档主题）时，它确实会调用更新查询，但即使如此，它也不会保留数据库中的任何一对多更改。我需要改变什么才能让它工作？

Getter and setter for DocumentPersonCc:

DocumentPersonCc 的 getter 和 setter：

@OneToMany(fetch = FetchType.LAZY, mappedBy = "document")
@LazyCollection(LazyCollectionOption.EXTRA)
@Sort(type = SortType.NATURAL, comparator = DocumentPersonCc.class)
public SortedSet<DocumentPersonCc> getDocumentPersonCcs() {
    return this.documentPersonCcs;
}

public void setDocumentPersonCcs(
        SortedSet<DocumentPersonCc> documentPersonCcs) {
    this.documentPersonCcs = documentPersonCcs;
}

Update Code:

更新代码：

public Document updateCcs(Document document) {
    Session session = HibernateUtil.getSessionFactory().getCurrentSession();
    session.beginTransaction();
    Document oldD = (Document) session.load(Document.class, document.getId());
    Hibernate.initialize(oldD.getDocumentPersonCcs());
    oldD.setDocumentPersonCcs(document.getDocumentPersonCcs());
    session.update(oldD);
    session.getTransaction().commit();
    document = this.returnDocument(document.getId());
    Hibernate.initialize(document.getDocumentPersonCcs());
    return document;
}

DocumentPersonCc's Document getter and setter:

DocumentPersonCc 的 Document getter 和 setter：

@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "DocumentsId", nullable = false, insertable = false, updatable = false)
protected Document getDocument() {
    return this.document;
}

public void setDocument(Document document) {
    this.document = document;
}

回答by Pramod Kumar

Try this -

试试这个 -

@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "document")
@LazyCollection(LazyCollectionOption.EXTRA)
@Sort(type = SortType.NATURAL, comparator = DocumentPersonCc.class)
public SortedSet<DocumentPersonCc> getDocumentPersonCcs() {
    return this.documentPersonCcs;
}

Use cascade to update child mapping

使用级联更新子映射

回答by Niroshan Abayakoon

use cascade in your Document entity class. `

在您的 Document 实体类中使用级联。`

@OneToMany(fetch = FetchType.LAZY, mappedBy = "document")
@LazyCollection(LazyCollectionOption.EXTRA)
@Sort(type = SortType.NATURAL, comparator = DocumentPersonCc.class)
@Cascade({CascadeType.SAVE_UPDATE}) 
public SortedSet<DocumentPersonCc> getDocumentPersonCcs() {
    return this.documentPersonCcs;
}

` Then when you save or update collection when you save or update document entity.

` 然后当您保存或更新集合时保存或更新文档实体。

回答by Rahul Agrawal

In your Document.java add one method as

在你的 Document.java 添加一个方法作为

 public void addDocumentPersonCc(DocumentPersonCc documentPersonCc) {
    documentPersonCc.setDocument(this);
    documentPersonCcs.add(documentPersonCc);
 }

Now change your updateCcs method as

现在将您的 updateCcs 方法更改为

public Document updateCcs(Document document) {
    Session session = HibernateUtil.getSessionFactory().getCurrentSession();
    session.beginTransaction();
    Document oldD = (Document) session.load(Document.class, document.getId());
    Hibernate.initialize(oldD.getDocumentPersonCcs());
    SortedSet<DocumentPersonCc> documentPersonCcsList = document.getDocumentPersonCcs();
    //Iterate this documentPersonCcsList

    {
        // add oldD.addDocumentPersonCc(Value from Iterator);
    }    
    session.update(oldD);
    session.getTransaction().commit();
    document = this.returnDocument(document.getId());
    Hibernate.initialize(document.getDocumentPersonCcs());
    return document;
}