java - 当子实体被删除时，Hibernate 确实执行更新而不是删除操作

Question

当我从子列表(历史)中删除旧行时，我有两个实体，父(项目)具有历史实体列表item.getHistories().remove(0) 我希望 hibernate 对子行执行删除操作，但 hibernate 将外键更新为 null。此更新会导致NOT NULL VIOLATION，因此外键具有NOT NULL 约束。

这是我的父实体:

@Data
@EqualsAndHashCode(callSuper = true)
@Entity
@Table(name = "item", schema = "public", catalog = "foo")
public class RepricingItem extends BaseDatesEntity {

    @Id
    @SequenceGenerator(name="item_id_seq", sequenceName = "item_id_seq", allocationSize = 5)
    @GeneratedValue(strategy = SEQUENCE, generator = "item_id_seq")
    @Column(name = "id", unique = true, insertable = true, updatable = false, nullable = false)
    protected Long id;

    @Size(min = 1, max = 100)
    @Column(name = "title", nullable = false, insertable = true, updatable = true)
    private String title;

    @OneToMany(fetch = LAZY, cascade = ALL, orphanRemoval = true)
    @JoinColumn(name = "item_id")
    private List<ItemHistory> histories;
}

这是 child :

@Data
@EqualsAndHashCode(callSuper=true)
@Entity
@Table(name = "item_history", schema = "public", catalog = "foo")
public class RepricingItemBuyBoxHistory extends BaseEntity {

    @ManyToOne(fetch = LAZY, optional = false)
    @JoinColumn(name = "item_id", nullable = false, updatable = false)
    private RepricingItem repricingItem;

    @Size(min = 1, max = 255)
    @Column(name = "some_history_data", nullable = false, insertable = true, updatable = false)
    private String someHistoryData;
}

这是具有非空约束的历史表:

CREATE TABLE "item_history" (
    id                BIGSERIAL PRIMARY KEY,
    item_id           BIGINT                      NOT NULL REFERENCES "item" (id) ON DELETE CASCADE,
    inserted          TIMESTAMP WITHOUT TIME ZONE,
    updated           TIMESTAMP WITHOUT TIME ZONE,
    some_history_data VARCHAR(255)                NOT NULL
) WITH (OIDS =FALSE);

这是hibernate生成的更新子句:

11:17:00,794 WARN  [org.hibernate.engine.jdbc.spi.SqlExceptionHelper] SQL Error: 0, SQLState: 23502
11:17:00,794 ERROR [org.hibernate.engine.jdbc.spi.SqlExceptionHelper] Batch entry 0 update foo.public.item_history set item_id=null where item_id=903372 and id=245 was aborted.  Call getNextException to see the cause.

我怎样才能告诉hibernate删除 child 而不是尝试删除关系。

Answer 1

我认为您需要将“mappedBy”属性添加到 RepricingItem 中的 @OneToMany 注释中。我想是这样的:

@OneToMany(fetch = LAZY, cascade = ALL, orphanRemoval = true, mappedBy = "repricingItem")
@JoinColumn(name = "item_id")
private List<ItemHistory> histories;

问题与哪个实体是“所有者”有关。比我能给出的更好的解释可以在这里找到: inverse = “true” example and explanation