Spring Boot findById 不工作，但 findAllById 工作正常

Question

我有一个如下定义的投标实体

@ToString
@NoArgsConstructor
@AllArgsConstructor
@Setter
@Getter
@Entity
@Table(name = "bid_details")
public class Bid {

    private enum STATUS { INITIATED, DRAFT, COMPLETED }

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", nullable = false, updatable = false)
    private Integer id;

    @Column(name = "govt_bid_id", nullable = false)
    private String govtBidNumber;

    @Temporal(TemporalType.DATE)
    @Column(name = "release_date", nullable = false)
    @JsonFormat(pattern = "dd-MM-yyyy")
    private Date releaseDate;

    @ManyToOne(optional = false)
    @JoinColumn(name = "created_by", referencedColumnName = "id", updatable = false, nullable = false)
    private User createdBy;

    @Temporal(TemporalType.DATE)
    @Column(name = "created_date", nullable = false)
    @CreationTimestamp
    private Date createdDate;

    @ManyToOne
    @JoinColumn(name = "updated_by", referencedColumnName = "id", updatable = false, nullable = false)
    private User updatedBy;

    @Enumerated(EnumType.STRING)
    @Column(name = "status", nullable = false)
    private STATUS status;

    @Column(name = "avg_turnover")
    private String avgTurnover;

    @Convert(converter = StringListConverter.class)
    @Column(name = "docs_required", columnDefinition = "json")
    private List<String> docsRequired;

   @Enumerated(EnumType.STRING)
   @Column(name = "status", nullable = false)
   private STATUS status;

}

并且相应的列存在于bid_details 表中。我的投标存储库定义如下：

public interface BidRepository extends JpaRepository<Bid, Integer> {
}

现在，当我尝试使用 findById 通过 id 访问数据时，它会抛出 No Value Present 异常，而如果我尝试使用 findAllById 访问数据，我会得到正确的结果。无法弄清楚是什么导致了这种奇怪的行为。

另外，如果我先执行findAll，然后执行findById，它会给出正确的结果。

我使用的是 spring-boot 版本 2.1.1

以下是实体保存在数据库中的代码

public Bid addBid(BidRequest bidRequest) {
        User user = userRepository.findById(bidRequest.getCreatedBy()).get();
        Bid bid = new Bid();
        modelMapper.map(bidRequest, bid);
        bid.setCreatedBy(user);
        return bidRepository.save(bid);
    }

BidRequest 类如下：

@ToString
@NoArgsConstructor
@AllArgsConstructor
@Setter
@Getter
public class BidRequest {

    private String govtBidNumber;

    @Temporal(TemporalType.DATE)
    @JsonFormat(pattern = "yyyy-MM-dd")
    private Date releaseDate;

    @Temporal(TemporalType.DATE)
    private Date endDate;

    private int createdBy;

    @Temporal(TemporalType.DATE)
    @JsonFormat(pattern = "yyyy-MM-dd")
    private Date createdDate;

    private int updatedBy;

    private String status;

    private List<String> docsRequired;

}

Answer 1

你试过orElse这样的

findById(id).orElse(null);

因为findById返回一个Optional对象所以你必须在findById()之后写orElse()