Hibernate级联删除依赖实体（ManyToOne OneToMany）答案

【问题标题】：Hibernate cascade delete dependent entities (ManyToOne OneToMany)Hibernate级联删除依赖实体（ManyToOne OneToMany）
【发布时间】：2020-06-25 11:23:53
【问题描述】：

在项目中有实体帐户和服务（摘要）。服务有一个子类，存款。帐户类代码：

@Entity
public class Account {
  private static Logger log = LogManager.getLogger(Account.class);

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private long id;
  @Column
  private double amount;
  @Column
  private AccountType type;
  @Column(name = "date_start")
  private Date dateStart;
  @Column(name = "date_end")
  private Date dateEnd;
  @Column(name = "in_rate")
  private short inRate;
  @ManyToOne
  @JoinColumn(name = "client_id")
  private Client client;
...

服务类代码：

@MappedSuperclass
abstract public class Services {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  protected long id;
  @ManyToOne(cascade=CascadeType.ALL)
  @JoinColumn(name = "from_acc_id")
  protected Account fromAcc;
...

存款还有一个金额字段，但这不是那么重要：

@Entity
public class Deposit extends Services {
  @Column
  private double amount;

当尝试删除存在来自 Deposit 的链接的 Account 实例时，它会给出错误：

2020-03-13 13:29:51 ERROR SqlExceptionHelper: 131 - ERROR: UPDATE or DELETE in the "account" table violates the foreign key constraint "fk8qcea1frw0og19kft1ltq9kf9" of the "deposit" table
Details: The key (id) = (1) still has links in the "deposit" table.

如何配置级联删除，以便在删除账户记录时，自动删除存款记录？

【问题讨论】：

存款实体在哪里？
通过向您的 Account 实体添加 OneToMany 映射并在其上放置级联配置？
@Gimby，它不起作用。

标签： java hibernate jpa one-to-many hibernate-mapping

【解决方案1】：

一般来说，@OnDelete 注释很有帮助。 Account 类没有改变。服务代码：

@MappedSuperclass
abstract public class Services {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  protected long id;
  @ManyToOne(cascade = CascadeType.REFRESH)
  @JoinColumn(name = "from_account_id")
  @OnDelete(action = OnDeleteAction.CASCADE)
  protected Account fromAcc;
...

【讨论】：