Question

我有两个DTO：

@Entity
@Table( name = "USER" )
public class UserDto implements Serializable 
{
    @Id
    @GeneratedValue( generator = "trigger_gen" )
    @GenericGenerator( name = "trigger_gen", strategy = "path.TriggerAssignedIdentityGenerator" )
    @Column( nullable = true, length = 14, name = "USER_ID" )
    private Long userId;

    @OneToMany( cascade =
    { CascadeType.ALL }, mappedBy = "userIdOwner" )
     private Set< AdressDto > addresses;

    //getters and setters
}

@Entity
@Table( name = "ADDRESS" )
public class AddressDto implements Serializable
{
    @Id
    @GeneratedValue( generator = "trigger_gen" )
    @GenericGenerator( name = "trigger_gen", strategy = "path.TriggerAssignedIdentityGenerator" )
    @Column( nullable = true, length = 14, name = "ADDRESS_ID" )
    private Long addressId;

    @Column( nullable = true, length = 14, name = "USER_ID", insertable = false, updatable = false )
    private Long userId;

    @ManyToOne( fetch = FetchType.LAZY )
    @JoinColumn( name = "USER_ID", insertable = true, updatable = true )
    private UserDto userIdOwner;

    //getters and setters
}

我想做类似的事情：

AddressDto address = new AddressDto();
Set<AddressDto> addresses = Sets.newHashSet();
addresses.add(address);

UserDto user = new UserDto()
user.setAddresses(addresses);

session.persist(user);

但是我有一个错误ConstraintViolationException无法将'NULL'设置为addressId。我究竟做错了什么？我该怎么做才能使它有效？

Answer 1

您需要在两个方向上关联实体才能使级联工作。

AddressDto address = new AddressDto();
UserDto user = new UserDto()

user.getAddresses().add(address);
address.setUser(user);

session.persist(user);

我在你的地址实体中注意到了这一点：

   @Column( nullable = true, length = 14, name = "USER_ID", insertable = false, updatable = false )
   private Long userId;

这似乎是不必要的，因为您User映射为@ManyToOne正好在

下面

使用触发器生成的id保存OneToMany关系

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