呼叫findAllById時，JPA存盤庫未獲取新資料以前的資料僅存在于參考的變數中

我正在嘗試獲取類別明智的問題并將 categoryList 傳遞給另一個名為 Location 的物件，如下所示

Location:
{
 List<Category> categoryList;
}

Category:
{
 List<Question> questions;
 Status status;
}

for (Category category : categories) {
    List<Question> questions = new ArrayList<>();
    questions = questionRepo.findAllById(category.getQuestionIds());
    category.setQuestions(questions);
    category.setStatus(updateQuestionStatus(questions));
    catList.add(category);
}

在嘗試從回圈中的表中獲取資料時。JPA存盤庫findAllById()在第一次迭代中回傳正確的資料。在我的資料庫中，狀態將始終為null. 我獲取問題串列并根據一些邏輯將狀態更新為INPROGRESS或TODO

在下一次迭代中，它不是獲取一組新資料，而是回傳先前創建的questions變數實體，其中狀態已經從上一次迭代中設定，而不是null.

所以最后說出所有五個具有相同 CategoryList 問題的 Location 物件。

我除錯了我的代碼并將 repo 查詢呼叫歸零，這是 Spring JPA 而不是我的實作。

questions = questionRepo.findAllById(category.getQuestionIds());

In the line before this on debug the questions is [] as expected. But when this line is executed i get a copy of the previously altered questions. with status as INPROGRESS or TODO that i set.

I tried lots of things like addAll into a new list etc still no luck. Please help. Thanks in Advance.

UPDATE:

Sharing the Question Entity for better help.

@Entity
@Table(name = "m_question")
@Data
@EqualsAndHashCode(callSuper = false)
@JsonInclude(value = Include.NON_NULL)
@JsonIgnoreProperties(value = { "addedBy", "addedOn", "updatedBy", "updatedOn","deleted" })
public class Question extends Auditable<String> {
    
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "m_question_id")
    private int mQuestionId;
    
    @Column(name = "m_q_category_id")
    private int mQCategoryId;
    
    @Column(name = "category_code")
    private String categoryCode;
    
    @Column(name = "m_q_section_id")
    private int mQSectionId;
    
    @Column(name = "section_code")
    private String sectionCode;
    
    @Column(name = "question_display")
    private String questionDisplay;
    
    @Column(name = "max_mark")
    private int maxMark;
    
    @Column(name = "more_info")
    private String moreInfo;
    
    @Column(name = "special_info")
    private String specialInfo;
    
    @Column(name = "option_type")
    private String optionType;
    
    @Column(name = "display_order")
    private Integer displayOrder;
    
    @Column(name = "is_deleted")
    private boolean isDeleted;
    
    @Column(name = "question_condition")
    private String questionCondition;
    
    @Transient
    private QuestionStatus status;
    
    @Transient
    @JsonSerialize
    @JsonDeserialize
    private List<Option> options;
}

So as shown above the Question entity doesnt change much in table values. But when i fetch those questions i check if any options relevant to the question are present and update the status field to TODO or INPROGRESS which should initially be null but not.

I even tried fetching all the questions (around 500) of them initially and putting them in a map and fetching when required from the map still the same issue is there.

Am not sure what I am doing wrong here.

uj5u.com熱心網友回復：

我能夠通過在findAllById通話前清除物體管理器來解決此問題。這似乎打破了對先前獲取的物件的參考，允許我向回圈中的每個元素添加新實體。

盡管因此在代碼或物件檢索/持久性方面沒有遇到任何其他問題，但我不能 100% 確定這是正確的解決方案。

現在我的問題已經解決了。

@Autowired
EntityManager em;

for (Category category : categories) {
    List<Question> questions = new ArrayList<>();
    //Clearing the entityManager instance.
    em.clear();
    questions = questionRepo.findAllById(category.getQuestionIds());
    category.setQuestions(questions);
    category.setStatus(updateQuestionStatus(questions));
    catList.add(category);
}

歡迎任何更好的解決方案或實作。謝謝。

標籤：java spring-boot hibernate jpa spring-data-jpa

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