我將從結果開始。在下一張圖片中，我將顯示 company.userAccount 的結果內容。在數據庫中，我只有兩家公司分配給同一個用戶，其中一家公司有 7 項服務。@Entity@Table(name = "user_account")@Data@Introspected@JsonIgnoreProperties(value = {"id"})public class UserAccount {    ...    @OneToMany(mappedBy = "userAccount", fetch = FetchType.EAGER)    private List<Company> companies = new ArrayList<>();}@Entity@Table(name = "company")@Data@Introspected@ToString(exclude = {"userAccount"})@JsonIgnoreProperties(value = {"id", "userAccount"})public class Company {    ...    @ManyToOne(optional = false)    @JoinColumn(name = "user_account_id", updatable = false, nullable = false)    private UserAccount userAccount;}@Entity@Table(name = "service")@Data@Introspected@ToString(exclude = {"company"})@JsonIgnoreProperties(value= {"id", "company"})public class Service {    ...    @ManyToOne(optional = false)    @JoinColumn(name = "company_id", updatable = false, nullable = false)    private Company company;}@Transactionalpublic Service saveService(@Valid @Uuid UUID companyUuid, SaveServiceCommand command) {    Company company = companyRepository.getCompanyByUuid(companyUuid).orElseThrow(() -> new NoSuchElementException("unrecognized company"));    Service service = new Service();    service.setCompany(company);    service.setName(command.getName());    service.setUuid(UUID.randomUUID().toString());    return companyRepository.saveCompanyService(service);}@Transactionalpublic Service saveCompanyService(@Valid Service service) {    entityManager.persist(service);    return service;}生成的查詢（簡化）是select * from user_account a left outer join company c on a.id=c.user_account_id left outer join service s on c.id=s.company_id; 這將產生預期結果：我期望在 UserAccount 中只看到 2 家公司，其中一家公司有 6 項服務。為什么我會有這個結果？為什么同一個公司對象多次出現在列表中？我怎樣才能避免這種情況？我相信一種解決方案是將 @OneToMany 關系的獲取類型更改為 LAZY （因為它們是默認的）（已經測試了該解決方案并且它有效），但是如果我需要這種類型的場景怎么辦？