Question

我有两个连接的类，

病人：

...
@Entity
@Table(schema="public",name="patient")  
public class Patient{
..
@Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "patient_id")
    public Integer getId() {
        return Id;
    }
    public void setId(Integer id) {
        Id = id;
    }

@ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL) 
    @JoinTable(name = "patient_examination", catalog = "ALTAdb", joinColumns = { 
    @JoinColumn(name = "patient_id", nullable = false, updatable = false) }, 
    inverseJoinColumns = { @JoinColumn(name = "examination_id",nullable = false, updatable = false) })
    public Set<Examination> getExaminations() {
        return examinations;
    }
    public void setExaminations(Set<Examination> examinations) {
        this.examinations = examinations;
    }
...

检查：

...
@Entity
@Table(schema="public",name="examination")  
public class Examination{
..
@Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "examination_id")
    public Integer getId() {
        return Id;
    }
    public void setId(Integer id) {
        Id = id;
    }
    @ManyToMany(fetch = FetchType.EAGER, mappedBy = "examinations") 
    public Set<Patient> getPatients() {
        return patients;
    }
    public void setPatients(Set<Patient> patients) {
        this.patients = patients;
    }
...

当我尝试删除在patient_examination中出现的记录时

代码：

public boolean deleteExamination(int ExaminationId){
    boolean deleted=false;
    Session session=factory.getCurrentSession();  
    session.beginTransaction(); 
    Query query =session.createQuery("select m from "+ Examination.class.getName() +" m");  
    List<Examination> examinations= query.getResultList();
    for(Examination e: examinations){
        if(e.getId()==ExaminationId){
            session.delete(e);
            deleted=true;
            break;
        }
    }
    session.getTransaction().commit(); 
    return deleted;
}

这是我的控制台：

"Examination" violates the external key constraint "fkexas9b9fwxn0t37wl60a4jcd3" on the table "patient_examination"
  Detail: The key (examination_id) = (4) is still referenced by the table "patient_examination"

我不知道如何解决它。

我也尝试过直接访问patient_examination的查询，但我不知道它的工作方法

Answer 1

使用CascadeType.REMOVE尝试@ManyToMany，据我所知，它会起作用...

Hibernate消除了许多关系中的记录和传播

1 个答案: