春季数据JPA删除

Question

我在尝试删除记录时遇到外键违规问题。

我有这个记录：

@Entity
public class Parent {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long parentId;

    @OneToOne(cascade = CascadeType.ALL, orphanRemoval = true)
    @JoinColumn(name = "childId")
    private Child child;

和

@Entity
@Table(name = "Child")
public class Child {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long childId;


    public Long getOperatoryId() {
        return id;
    }

当我尝试删除孩子时，我遇到了密钥违规，因为有一些父记录指向孩子。我想我可以先删除父母，然后去删除孩子：

parentRepository.delete(父)

但我收到一个错误，即属性 ID 不存在于子级。这是因为子id被命名为childId而不是id吗？

Answer 1

在这里，我处理了您要求的类似示例。根据您的需要对其进行自定义。

• SQL Server 表创建查询

   CREATE TABLE "DBO"."Parent"(
   Parent_Id INT PRIMARY KEY NOT NULL,
   Parent_Name VARCHAR(255) NOT NULL)
  
   CREATE TABLE "DBO"."Child"(
   Child_Id INT PRIMARY KEY NOT NULL,
   Child_Name VARCHAR(255) NOT NULL,
   Parent_Ref_Id int not null,
   CONSTRAINT FK_Parent_Ref_Id FOREIGN KEY (Parent_Ref_Id) REFERENCES Parent(Parent_Id)
  )
  

• Spring 数据 JPA 代码

父实体

    @Entity(name = "Parent")
    @Table(name = "Parent")
    public class Parent {

    @Id
    @Column(name = "Parent_Id")
    private long parentId;

    @Column(name = "Parent_Name")   
    private String parentName;

    //cascade = {CascadeType.REMOVE} OR orphanRemoval = true    
    @OneToOne(cascade = {CascadeType.ALL},orphanRemoval = true,fetch = FetchType.LAZY,mappedBy="parentInfo")    
    private Child childInfo;

    public long getParentId() {
        return parentId;
    }

    public void setParentId(long parentId) {
        this.parentId = parentId;
    }

    public String getParentName() {
        return parentName;
    }

    public void setParentName(String parentName) {
        this.parentName = parentName;
    }

    public Child getChildInfo() {
        return childInfo;
    }

    public void setChildInfo(Child childInfo) {
        this.childInfo = childInfo;
    }
    }

子实体

@Entity(name = "Child")
@Table(name = "Child")
public class Child {

    @Id
    @Column(name = "Child_Id")
    private int childId;

    @Column(name = "Child_Name")
    private String childName;

    @OneToOne
    @JoinColumn(name = "Parent_Ref_Id", referencedColumnName = "Parent_Id")
    private Parent parentInfo;

    public int getChildId() {
        return childId;
    }

    public void setChildId(int childId) {
        this.childId = childId;
    }

    public String getChildName() {
        return childName;
    }

    public void setChildName(String childName) {
        this.childName = childName;
    }

    public Parent getParentInfo() {
        return parentInfo;
    }

    public void setParentInfo(Parent parentInfo) {
        this.parentInfo = parentInfo;
    }

}

儿童回购代码

public interface ChildRepo extends CrudRepository<Child,Long> {

}

父回购代码

public interface ParentRepo extends CrudRepository<Parent,Long> {
    Parent findByParentId(long id);
}

控制器代码

@Autowired
private final ParentRepo parentRepo;
....

private void save() {
        //Save the parent
        Parent p = new Parent();
        p.setParentId(1);
        p.setParentName("Parent1");
        Child c = new Child();
        c.setChildId(1);
        c.setChildName("Child1");
        c.setParentInfo(p);
        p.setChildInfo(c);
        parentRepo.save(p);

        //delete the parent and child as well
        Parent p1 = parentRepo.findByParentId(1);
        parentRepo.delete(p1);
    }