Question

我想使用spring-jpa更新表

这是我的实体类

public class RewardEntity {

    @Id
    @Column(name = "reward_id", columnDefinition = "bigserial")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long rewardId;

    @Column(name = "reward_title", nullable = false)
    private String rewardTitle;

    @Column(name = "reward_text")
    private String rewardText;

    @Column(name = "reward_type", nullable = false)
    private String rewardType;

    @Column(name = "reward_for_code", nullable = false)
    private String rewardFor;

    @Column(name = "reward_from_date", nullable = false)
    private OffsetDateTime rewardFromDate;

    @Column(name = "reward_to_date", nullable = false)
    private OffsetDateTime rewardToDate;

    @Column(name = "is_display_on", nullable = false)
    private Boolean isDisplayOn;

    @Column(name = "created_id", length = 50, nullable = false)
    private String createdId;

    @Column(name = "updated_id", length = 50)
    private String updatedId;

    @Column(name = "created_date", columnDefinition = "timestamptz", nullable = false)
    private OffsetDateTime createdDate;

    @Column(name = "last_modified_date", columnDefinition = "timestamptz")
    private OffsetDateTime lastModifiedDate;

}

我有一个PutMapping春季靴子API，低于Json Input

{
    "rewardId": 53,
    "rewardTitle": "Reward is Allocated",
    "rewardText": "Reward allocated for your recent purchase with our shop located at ABC-Mall",
    "rewardType": "Informational",
    "rewardFor": "Customer",
    "rewardFromDate": "2019-04-12T00:00:00+05:30",
    "rewardToDate": "2019-04-15T00:00:00+05:30",
    "isDisplayOn": false
}

我的控制器将Principal对象用于创建和更新 rewards表

@PutMapping
    public ResponseEntity<RewardsResponse> updateRewards(Principal updatedPrincipal,
                                                                   @RequestBody RewardUpdateRequest RewardUpdateRequest) {

但是我不会从Angular-UI发送我的createdId或updatedId。因此，当我尝试使用以下服务层代码将更新的实体插入表中时

 public RewardEntity updateReward(Principal principal, rewardEntity rewardEntity) {
        String updatedId = null != principal ? principal.getName() : "defaultUpdatedId";
        rewardEntity.setUpdatedCdsId(updatedId);
        rewardEntity.setLastModifiedDate(OffsetDateTime.now());
        return rewardRepository.save(rewardEntity);
}

我收到以下错误

could not execute statement; SQL [n/a]; constraint [created_id]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement

我的假设是，通过映射我们传递的RewardEntity并仅更新我设置的ID而不涉及其余字段，可以在同一行中更新fields。 ..

我应该首先根据ID从数据库中获取我的RewardEntity对象，然后在其之上进行更新吗？这样，代码每次更新都会两次连接数据库。

请输入您的意见

Answer 1

我首先要使用updatedId

获取参考对象

RewardEntity rewardEntity = rewardRepository.getOne(updatedId )

根据您的要求更新此对象

rewardEntity.setLastModifiedDate(OffsetDateTime.now());

最后使用save进行更新。

return rewardRepository.save(rewardEntity);

getOne()返回对该实体的引用，并在内部调用EntityManager.getReference()方法。它将始终返回代理，而不会访问数据库（延迟获取）。

Spring Data JPA更新行而不获取行ById

1 个答案: