为单个用户创建信用卡时，它只会更新以前的卡而不是添加新卡

Question

(1) 在这个 SpringBoot 应用程序上使用 @OneToMany 和 @ManyToOne 只是使关系成为一对一。这个想法是让一个用户可以拥有多张卡片。每次新卡片为@Post，它都会更新卡片而不是为用户创建新卡片。

(2) 实现信用卡更新、删除方法的任何想法。

信用卡Class

@Entity
@Table(name = "CreditCards")
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
public class CreditCard {

    @Id
    @Column(name = "username", nullable = false)
    private String username;
    @Column(name = "cardName")
    private String cardName;
    @Column(name = "cardNumber")
    private BigInteger cardNumber;
    @Column(name = "expirationDate")
    private Integer expirationDate;
    @Column(name = "securityCode")
    private Integer securityCode;

    @ManyToOne(fetch = FetchType.LAZY, optional = false)
    @JoinColumn(name = "user_id", nullable = false)
    @JsonIgnore
    private User user;

    //For Deserialization
    public CreditCard() {}

    public CreditCard(String username) {
        this.username = username;
    }

    public BigInteger getCardNumber() {
        return cardNumber;
    }

    public void setCardNumber(BigInteger cardNumber) {
        this.cardNumber = cardNumber;
    }

    public Integer getExpirationDate() {
        return expirationDate;
    }

    public void setExpirationDate(Integer expirationDate) {
        this.expirationDate = expirationDate;
    }

    public Integer getSecurityCode() {
        return securityCode;
    }

    public void setSecurityCode(Integer securityCode) {
        this.securityCode = securityCode;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public String getCardName() {
        return cardName;
    }

    public void setCardName(String cardName) {
        this.cardName = cardName;
    }
}

用户Class

    @Entity
@Table(name = "Users")
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
public class User {

    @Id
    @Column(name = "username")
    private String username;
    @Column(name = "password")
    private String password;
    @Column(name = "name")
    private String name;
    @Column(name = "address")
    private String address;
    @Column(name = "email")
    private String email;

    @OneToMany(mappedBy = "user", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    //@JoinColumn(name = "username")
    private List<CreditCard> creditCard;

    //For Deserialization
    public User() {
    }

    public User(String username) {
        this.username = username;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public List<CreditCard> getCreditCard() {
        return creditCard;
    }

    public void setCreditCard(List<CreditCard> creditCard) {
        this.creditCard = creditCard;
    }


}

用户资源Class

@RestController
@RequestMapping("/geektext")
public class UserResource {

    @Autowired
    private UserRepository userRepository;

    //Displays User By Username Search
    @GetMapping("/users/{username}")
    public User getUserByUsername(@PathVariable String username) {
        Optional<User> users = userRepository.findByUsername(username);
        if (users.isPresent()) {
            return users.get();
        } else{
                throw new RuntimeException("User '" + username + "' not found");
            }
        }

    //Displays List of All Users
    @GetMapping("/users")
    public List<User> getAllUsers() {
        return userRepository.findAll();
    }

    //Creates a New User
    @PostMapping("/users")
    public User loadUser(@RequestBody final User user) {
        user.setEmail(user.getUsername());
        return userRepository.save(user);
    }

    //Creates a List of New Users
    @PostMapping("/users/all")
    public List <User> loadAllUsers(@RequestBody final List <User> users) {
        return userRepository.saveAll(users);
    }

    //Updates an Existing User
    @PutMapping("/users/{username}")
    public User updateUser(@PathVariable String username, @RequestBody User user) {
        return userRepository.save(user);
    }

    //Deletes an Existing User
    @DeleteMapping("/users/{username}")
    public String deleteUser(@PathVariable String username) {
        Optional<User> users = userRepository.findById(username);
        if (users.isPresent()) {
            userRepository.delete(users.get());
            return "User '" + username + "' has been deleted";
        } else {
            throw new RuntimeException("User '" + username + "' not found");
        }
    }

}

信用卡资源Class

@RestController
@RequestMapping("/geektext/users")
class CreditCardResource {

    @Autowired
    CreditCardRepository cardsRepository;

    @Autowired
    UserRepository userRepository;

    //Displays CreditCard By Username Search
    @GetMapping("/{userID}/cards")
    public Optional<CreditCard> getCardsByUsername(@PathVariable String userID) throws NotFoundException {
        if (!userRepository.existsById(userID)){
            throw new NotFoundException("User '" + userID + "' not found");
        }
        return cardsRepository.findByUsername(userID);
    }

    //Creates New Card for User
    @PostMapping("/{userID}/cards")
    public CreditCard loadCard(@PathVariable String userID, @RequestBody CreditCard creditCard) throws NotFoundException {
        if (userRepository.existsById(userID)) {
            creditCard.setUsername(userID);
        }
        return userRepository.findByUsername(userID).map(user -> {creditCard.setUser(user);
        return cardsRepository.save(creditCard);
        }).orElseThrow(() -> new NotFoundException("User '" + userID + "' not found"));

    }

}

用户存储库接口

    @Repository
public interface UserRepository extends JpaRepository<User, String> {
    //Optional<User> findByName(String name);
    Optional<User> findByUsername(String username);

}

CreditCardRepository 接口

@Repository
public interface CreditCardRepository extends JpaRepository<CreditCard, String> {
    Optional<CreditCard> findByUsername(String username);
}

Answer 1

你应该在注释中添加 @ManyToOne() value cascade = CascadeType.Persist.

    @ManyToOne(fetch = FetchType.LAZY, optional = false, cascade = CascadeType.Persist)
    @JoinColumn(name = "user_id", nullable = false)
    @JsonIgnore
    private User user;

为单个用户创建信用卡时，它只会更新以前的卡而不是添加新卡

When creating Credit Cards for a single user, it only updates the previous card instead of adding a new one

spring-boot

jpa

spring-data-jpa

one-to-many

many-to-one