Java Hibernate + spring-data：父級持久化時Cascading Childs不工作

Question

我有一個Parent-Child重新分配，當我嘗試通過Parent上的更新添加新的Child時，我的問題就開始了。

當我的父是短暫的，一切正常

CreditCard cc = new CreditCard("1234"); 

    //User 
    User u1 = new User("KILLER"); 
    u1.addCreditCard(cc); // bi-directional happens here inside. 

    // An autowired Spring Data repository that implements CrudRepository 
    userRepository.save(u1); 

    Assert.assertEquals(1, u1.getCreditCardCollection().size()); 
    Assert.assertNotNull 
    (
      u1.getCreditCardCollection() 
      .stream() 
      .findFirst() 
      .get() 
      .getIdCreditCard() 
    ); 

測試以上成功地執行，並且用於CC對象產生的ID。

但是當我做：

User u2 = new User("Foo Bar McLoud"); // u2 is transient 

    userRepository.save(u2); // Now u2 is persistent 

    u2 = userRepository.findOne(u2.getIdLogin());// just to be sure I´m working with a persistent object ;) 

    CreditCard ccNew = new CreditCard("77777"); 

    u2.addCreditCard(ccNew);// bidirectional happens here inside 

    userRepository.save(u2); // should insert a new credit card right??? 

    Assert.assertEquals("User should have 1 credit card.", 
      1, u2.getCreditCardCollection().size()); // PASS 

    Set<CreditCard> ccs = u2.getCreditCardCollection(); 
    for (CreditCard cc : ccs) { 
     Assert.assertNotNull("CreditCard ID is null", cc.getIdCreditCard()); // FAIL: id is not generated. The database entry was not set. Added credit card is still transient... 
    } 

所以，在我的第二個測試，我ccNew仍然是其母公司更新後短暫的。

爲什麼它仍然是瞬態的？

子配置：

@JoinColumn(name = "id_user") 
@ManyToOne(optional = false) 
private User user; 

父配置：

@OneToMany(mappedBy = "user",cascade=javax.persistence.CascadeType.ALL) 
    private Set<CreditCard> creditCardCollection = new HashSet<>(); 

Answer 1

你一個事務內部測試工作，這和你一起工作（U2：

@OneToMany(mappedBy = "user") 
@org.hibernate.annotations.Cascade(org.hibernate.annotations.CascadeType.ALL) 
private Set<CreditCard> creditCardCollection = new HashSet<>(); 

的家長已經嘗試過.getCreditCardCollection（））與對象的值不與實體（保存尚未執行）：

Assert.assertEquals（「User should have 2 credit cards。」， 1，u2.getCreditCardCollection（）。size（））;

當您遍歷u2.getCreditCardCollection（）並檢查id時，它們爲null，因爲插入和id生成僅在commit階段或flush/clear上下文中出現。

您需要調用saveAndFlush（）而不是save（）。

u2 = userRepository.findOne(u2.getIdLogin()); 

    CreditCard ccNew = new CreditCard("77777"); 

    u2.addCreditCard(ccNew);// bidirectional happens here inside 

    userRepository.saveAndFlush(u2); 

    Assert.assertEquals("User should have 2 credit cards.", 
      1, u2.getCreditCardCollection().size()); // PASS 

    Set<CreditCard> ccs = u2.getCreditCardCollection(); 
    for (CreditCard cc : ccs) { 
     Assert.assertNotNull("CreditCard ID is null", cc.getIdCreditCard()); 
    } 

from api;

void flush（）刷新數據庫的所有掛起更改。

小號saveAndFlush（S實體） 保存一個實體，你在使用`userRepository.save`方法立即刷新變化