違反外鍵約束JPA

Question

我在這里有我的拍賣行項目和3個實體：

public class Auction implements Serializable {

private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
@ManyToOne
private UserAccount user; //nie daje sie id tylko obiekt
private String description;
private String title;
private double price;
@OneToMany(mappedBy = "auction", orphanRemoval = true, cascade = CascadeType.ALL, fetch = FetchType.EAGER)
private List<Offer> offers = new LinkedList<Offer>();
 private Timestamp creationTimestamp = new Timestamp(System.currentTimeMillis());
 private Timestamp expirationTimestamp;


public void addOffer(Offer o) {
    offers.add(o);
    o.setAuction(this);
}




public class Offer implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private double price;
    @ManyToOne
    private Auction auction;
    @ManyToOne
    private UserAccount user;
    private Timestamp creationTimestamp = new Timestamp(System.currentTimeMillis());

public class UserAccount implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String username;
    private String email;
    @OneToMany(mappedBy = "user", orphanRemoval = true, cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    private List<Offer> offers = new LinkedList<Offer>();
    @OneToMany(mappedBy = "user",fetch = FetchType.EAGER, orphanRemoval = true, cascade = CascadeType.ALL)
    private List<Auction> auctions = new LinkedList<Auction>();

public void addAuction(Auction a) {
    auctions.add(a);
    a.setUser(this);
}

public void addOffer(Offer o, Auction a) {
    offers.add(o);
    o.setUser(this);
    o.setAuction(a);
}

將數據添加到數據庫的過程很順利，但是刪除鏈接的行僅適用於UserAccount。 首先，我創建用戶，然后添加帶有報價的拍賣。 當我嘗試刪除用戶的拍賣錯誤時：

Internal Exception: org.apache.derby.shared.common.error.DerbySQLIntegrityConstraintViolationException: DELETE on table 'AUCTION' caused a violation of foreign key constraint 'OFFER_AUCTION_ID' for key (1).  The statement has been rolled back.
Error Code: 20000
Call: DELETE FROM AUCTION WHERE (ID = ?)
    bind => [1 parameter bound]

您能否告訴我解決方案是什么，我是否正確地認為這是關系錯誤，在這種情況下拍賣和用戶不應共享報價？ 測試代碼：

    UserAccount user = new UserAccount();
    user.setUsername("filip");
    user.setEmail("example100@gmail.com");

    Offer offer = new Offer();
    offer.setPrice(2200d);
    Offer offer2 = new Offer();
    offer.setPrice(2500d);

    Auction auction = new Auction();
    auction.setDescription("opel na sprzedaz");
    auction.setPrice(2000d);
    auction.setTitle("opelek na sprzedaz");
    auction.addOffer(offer);
    auction.setExpirationTimestamp(new Timestamp(System.currentTimeMillis() - 86400000l));

    user.addOffer(offer, auction);
    user.addOffer(offer2, auction);

    user.addAuction(auction);

    userEjb.save(user);

Answer 1

看來您的項目中正在使用EJB spring + hibernate解決方案。 數據庫中可能有2個表的用戶和提供。 並且它們通過外鍵關聯。 當前錯誤的原因不是關系故障。 您需要檢查用戶表和報價表中外鍵的“刪除時”字段是否設置為“ CASCADE”。