java - 如何在一对多 hibernate 中向现有数据插入或添加新行

Question

有两个表，一个是用户，另一个是用户地址详细信息。

在这里，用户将添加新的详细信息，我需要插入到多个边表中。

这里是一对多的关系。我已向表中添加新值，但没有删除现有关系。

但就我而言，发生的情况是旧关系被删除，新关系被添加。

实体类:

洗涤顺序:

@Entity(name = "ClothDetails")
public class WashingOrder {

@Id
@SequenceGenerator(name = "orderNo", sequenceName = "orderNo")
@GeneratedValue(strategy = GenerationType.AUTO, generator = "orderNo")
@Column(name = "orderNo")
private Long orderNo;

@Column(name = "totalClothes", nullable = false)
@NotNull
private Integer totalClothes;

@Column(name = "mensCloth", nullable = true)
private Integer mensCloth;

@Column(name = "womensCloth", nullable = true)
private Integer womensCloth;

@Column(name = "otherCloth", nullable = true)
private Integer otherClothes;

@Column(name = "deliveryDate", nullable = true)
@DateTimeFormat(pattern = "yyyy-mm-dd")
private Date deliveryDate;

@Column(name = "status", nullable = true)
private String orderStatus;

public Long getOrderNo() {
    return orderNo;
}

public void setOrderNo(Long orderNo) {
    this.orderNo = orderNo;
}

public Integer getTotalClothes() {
    return totalClothes;
}

public void setTotalClothes(Integer totalClothes) {
    this.totalClothes = totalClothes;
}

public Integer getMensCloth() {
    return mensCloth;
}

public void setMensCloth(Integer mensCloth) {
    this.mensCloth = mensCloth;
}

public Integer getWomensCloth() {
    return womensCloth;
}

public void setWomensCloth(Integer womensCloth) {
    this.womensCloth = womensCloth;
}

public Integer getOtherClothes() {
    return otherClothes;
}

public void setOtherClothes(Integer otherClothes) {
    this.otherClothes = otherClothes;
}

public Date getDeliveryDate() {
    return deliveryDate;
}

public void setDeliveryDate(Date deliveryDate) {
    this.deliveryDate = deliveryDate;
}

public String getOrderStatus() {
    return orderStatus;
}

public void setOrderStatus(String orderStatus) {
    this.orderStatus = orderStatus;
}

用户信息:

@Entity(name = "user")
public class UserInformation   {

private String firstName;

@Id
@SequenceGenerator(name = "userID", sequenceName = "userID")
@GeneratedValue(strategy = GenerationType.AUTO, generator = "userID")
@Column(name = "id")
private Long id;

private String lastName;

@Column(name = "reset", nullable = false)
private Integer passwordReset;

@Column(name = "useremail", nullable = false, unique = true)
@Email
@NotEmpty
private String email;
@Column(name = "password", nullable = false)
private String password;

@OneToOne(mappedBy = "user", optional = true, cascade = CascadeType.ALL, fetch = FetchType.LAZY)
@JoinColumn(name = "id")
private Role role;

@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
@JoinColumn(name = "id")
private List<CreditCards> creditCards;

@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
@JoinColumn(name = "user_id", referencedColumnName = "id")
private List<WashingOrder> orderList;

@Column(unique = true)
@NotEmpty(message = "{username}")
private String username;

public String getFirstName() {
    return firstName;
}

public Long getId() {
    return id;
}

public String getLastName() {
    return lastName;
}

public String getEmail() {
    return email;
}

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

public String getPassword() {
    return password;
}

public Role getRole() {
    return role;
}

public String getUsername() {
    return username;
}

public void setFirstName(String firstName) {
    this.firstName = firstName;
}

public void setId(Long id) {
    this.id = id;
}

public void setLastName(String lastName) {
    this.lastName = lastName;
}

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

public void setRole(Role role) {
    this.role = role;
}

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

public List<CreditCards> getCreditCards() {
    return creditCards;
}

public void setCreditCards(List<CreditCards> creditCards) {
    this.creditCards = creditCards;
}

public Integer getPasswordReset() {
    return passwordReset;
}

public void setPasswordReset(Integer passwordReset) {
    this.passwordReset = passwordReset;
}

public List<WashingOrder> getOrderList() {
    return orderList;
}

public void setOrderList(List<WashingOrder> orderList) {
    this.orderList = orderList;
}

代码:

    Session session = sessionFactory.getCurrentSession();
    long id = 1;
    Query query = session.createQuery("from user where id =" + id);
    UserInformation emp6 = (UserInformation) session.load(UserInformation.class, new Long(1));
    UserInformation user = (UserInformation) query.uniqueResult();
    List<WashingOrder> washingOrder = new ArrayList<WashingOrder>();
    washingOrder.add(order);
    System.out.println("washingOrder" + washingOrder);
    emp6.setOrderList(washingOrder);
    session.saveOrUpdate(user);

    Long orderID = (long) 1;
    return orderID;

数据库截图:

Answer 1

当您更新“user”时，“orderList”关系也会更新，因为您已在“orderList”上设置“cascade = CascadeType.ALL”。您的代码示例将 orderList 对象替换为全新的对象。因此删除所有以前的关系，并添加一个新的关系。

如果您想保留关系并仅添加新关系，则应使用检索到的对象中的列表:

List<WashingOrder> washingOrder = emp6.getOrderList();
washingOrder.add(order);    

确保预先加载“orderList”，因为您在该关系上启用了延迟加载。您可以通过以下方式执行此操作:

Hibernate.initialize(emp6.getOrderList());