jpa - JPA：当父实体被删除时，子实体仍然存在

Question

客户实体（父实体）

@Entity
public class Customer {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

private String name;

@OneToMany(mappedBy="customer", cascade=CascadeType.ALL)
private List<Facility> facilities;

//Setter and Getter for name and facilities

public void addFacility(Facility facility){
    if(this.facilities == null){
        this.facilities = new ArrayList<Facility>();
    }
    this.facilities.add(facility);
    facility.setCustomer(this);
}
}

设施实体（子实体）

@Entity
public class Facility {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

@ManyToOne
@JoinColumn(name="CUSTOMER_FK")
private Customer customer;

private String name;

//Setter and Getter, equals and hashcode
...
}

在Customer实体中，我使用CascadeType.ALL，但是当我删除客户时，相关的设施仍然存在。customer我删除

Query query = em.createNamedQuery("Customer.delete");
query.setParameter("id", customerId);
query.executeUpdate();

在哪里

@NamedQuery(name="Customer.delete", query="delete from Customer c where c.id = :id")

Answer 1

根据 JPA 规范，批量删除操作没有级联：

4.10 批量更新和删除操作

...

删除操作仅适用于指定类及其子类的实体。它不会级联到相关实体。

...

如果您想从级联中受益，请加载实体然后调用EntityManager#remove(Object)它。

Answer 2

尝试：

@Inject
EntityManager em;


Customer customer =...;
em.remove(customer);

这总是级联操作。