如何在两个外键上设置 Hibernate @ManyToMany 与级联的关联？

Posted 2023-04-12

【中文标题】如何在两个外键上设置 Hibernate @ManyToMany 与级联的关联？

【英文标题】：How to setup Hibernate @ManyToMany association with cascades on both foreign keys?

【发布时间】：2010-01-26 08:21:18

【问题描述】：

我正在尝试使用休眠映射@ManyToMany 关联。但到目前为止，我只设法在其中一个外键上进行级联。

我的源代码是这样的：

@Entity
public class Airplane 
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Long id;

    @OnDelete(action=OnDeleteAction.CASCADE)
    @ManyToMany(mappedBy="airplanes", cascade = CascadeType.ALL)
    private Set<Passenger> passengers;
...


@Entity
public class Passenger 
    @Id 
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Long id;

    @OnDelete(action=OnDeleteAction.CASCADE)
    @ManyToMany(cascade = CascadeType.ALL)
    private Set<Airplane> airplanes;
...

hibernatetool 输出：

create table Airplane (
    id bigint not null auto_increment,
    objVersion bigint,
    primary key (id)
) type=InnoDB;

create table Passenger (
    id bigint not null auto_increment,
    objVersion bigint,
    primary key (id)
) type=InnoDB;

create table Passenger_Airplane (
    passengers_id bigint not null,
    airplanes_id bigint not null,
    primary key (passengers_id, airplanes_id)
) type=InnoDB;

alter table Passenger_Airplane 
    add index FKC9262997C1630114 (airplanes_id), 
    add constraint FKC9262997C1630114 
    foreign key (airplanes_id) 
    references Airplane (id) 
    on delete cascade;

alter table Passenger_Airplane 
    add index FKC92629979BEE2B2 (passengers_id), 
    add constraint FKC92629979BEE2B2 
    foreign key (passengers_id) 
    references Passenger (id);

不知何故，Passenger 类上的 @OnDelete(action=OnDeleteAction.CASCADE) 注释被休眠丢弃了。

【参考方案1】：

嗯，不确定这是否有效。在HHH-4404 中查看非常古老的comment。