Postgresql – DESC is passed to a Hibernate query, but the order is still ascending. Why?

I have a RESTful app. Here’s a test method from it. It is intended to retrieve a page of QuestionCommentResponseDto objects in descending order

    @Test
    @Sql(executionPhase = BEFORE_TEST_METHOD, value = BASE_SCRIPT_PATH + "GetPageTest/before.sql")
    @Sql(executionPhase = AFTER_TEST_METHOD, value = BASE_SCRIPT_PATH + "GetPageTest/after.sql") // truncating
    public void getPageOneSizeFiveSortByIdDescTest() throws Exception {
        token = testUtil.getToken(testUsername, testPassword);
        MockHttpServletResponse response = mockMvc.perform(get(BASE_URI + "page/" + 1)
                        .header(HttpHeaders.AUTHORIZATION, token)
                        .param("pageSize", "5")
                        .param("sortType", "ID_DESC"))
                .andExpect(status().isOk())
                .andReturn()
                .getResponse();
// asserts omitted

<!-- the before script -->
TRUNCATE TABLE permissions CASCADE;
<!-- the same for accounts, questions, tags, question_comments -->

INSERT INTO permissions(id, name, created_date, modified_date)
VALUES (1, 'ADMIN', current_timestamp, current_timestamp),
       (2, 'MODERATOR', current_timestamp, current_timestamp),
       (3, 'USER', current_timestamp, current_timestamp);

INSERT INTO accounts(id, username, password, enabled, created_date, modified_date)
VALUES (1, 'mickey_m', '$2y$10$ZdqfOo1vwdHJJGnkmGrw/OUelZcU9ZfRFaX/RMN3XniXH96eTkB1e', true, current_timestamp,
        current_timestamp),
       (2, 'minerva_m', '$2y$10$PiZxGGi904rCLdTSGY1ycuQhcEtQrP1u74KvQ2IEuk5Jh18Ml.6xO', true, current_timestamp,
        current_timestamp);

INSERT INTO accounts_permissions(account_id, permission_id)
VALUES (1, 3),
       (2, 3);

INSERT INTO questions(id, created_date, modified_date, title, description, account_id)
VALUES (1, current_timestamp, current_timestamp, 'title', 'description', 2);

INSERT INTO tags(id, created_date, modified_date, name)
VALUES (1, current_timestamp, current_timestamp, 'tag1'),
       (2, current_timestamp, current_timestamp, 'tag2'),
       (3, current_timestamp, current_timestamp, 'tag3');

INSERT INTO questions_tags(question_id, tag_id)
VALUES (1, 1), (1, 2), (1, 3);

INSERT INTO question_comments(id, created_date, modified_date, text, account_id, question_id)
VALUES (1, current_timestamp, current_timestamp, 'text', 1, 1),
       <!-- the middle rows are omitted -->
       (10, current_timestamp, current_timestamp, 'text', 1, 1);

@Getter
public class QuestionCommentResponseDto {
    private final Long id;
    private final Long questionId;
    private final LocalDateTime createdDate;
    private final LocalDateTime modifiedDate;
    private final String text;
    @Setter
    private AccountResponseDto owner;

// constructors, equals(), hashcode()

@AllArgsConstructor
@NoArgsConstructor
@Getter
@Setter
public class AccountResponseDto {

    private Long id;
    private String username;

// equals(), hashcode()

// the relevant controller method
    @GetMapping("/page/{pageNumber}")
    public ResponseEntity<Data<Page<QuestionCommentResponseDto>>> getPage(@PathVariable @Positive @NotNull Integer pageNumber,
                                                                          @RequestParam(defaultValue = "20") @NotNull Integer pageSize,
                                                                          @RequestParam(defaultValue = "ID_ASC") @NotNull SortType sortType) {
        PaginationParameters params = PaginationParameters.ofPageNumberSizeAndSortType(pageNumber, pageSize, sortType);
// ↑ PaginationParameters is a simple record class defined as PaginationParameters(Integer pageNumber, Integer size, SortType sortType)
        Page<QuestionCommentResponseDto> page = dtoService.getPage(params);
        Data<Page<QuestionCommentResponseDto>> responseData = Data.build(page); // a two-bit wrapper
        return ResponseEntity.ok(responseData);
    }

@RequiredArgsConstructor
@Getter
public enum SortType {

    ID_ASC(" id "),
    ID_DESC(" id DESC "),
    // some extra constants

private String query;
}

// a basic utility class

public class PaginationParametersProcessor {
    public static String extractSortingModifier(PaginationParameters params) {
        return params.sortType().getQuery();
    }

    public static int extractFirstResultIndex(PaginationParameters params) {
        return (params.pageNumber() - 1) * params.size();
    }

    public static int extractMaxResults(PaginationParameters params) {
        return params.size();
    }
}

dtoService.getPage(params) eventually comes down to this

    @Override
    public List<QuestionCommentResponseDto> getDtosWithoutSetOwner(PaginationParameters params) {
        String sortingModifier = PaginationParametersProcessor.extractSortingModifier(params); // assigns " id DESC "
        int offset = PaginationParametersProcessor.extractFirstResultIndex(params);
        int limit = PaginationParametersProcessor.extractMaxResults(params);
        return entityManager.createQuery("""
                SELECT new stack.overflow.model.dto.response.QuestionCommentResponseDto (
                            qc.id, q.id, qc.createdDate, qc.modifiedDate, qc.text
                ) FROM QuestionComment qc JOIN qc.question q
                ORDER BY :sort
                """, QuestionCommentResponseDto.class)
                .setParameter("sort", sortingModifier)
                .setFirstResult(offset)
                .setMaxResults(limit)
                .getResultList();
    }

The :sort parameter is successfully passed into the query executed by Hibernate. Here’s a snippet from my console output

Hibernate: select questionco0_.id as col_0_0_, question1_.id as col_1_0_, questionco0_.created_date as col_2_0_, questionco0_.modified_date as col_3_0_, questionco0_.text as col_4_0_ from question_comments questionco0_ inner join questions question1_ on questionco0_.question_id=question1_.id order by ? limit ?
2023-06-04 16:46:53.164 TRACE 3172 --- [           main] o.h.type.descriptor.sql.BasicBinder      : binding parameter [1] as [VARCHAR] - [ id DESC ]

But the ids in the resulting list are in an ascending, not descending order

Body = {"data":{"dtos":[{"id":1,"questionId":1,"createdDate":"2023-06-04T16:46:52.942835","modifiedDate":"2023-06-04T16:46:52.942835","text":"text","owner":{"id":1,"username":"mickey_m"}},{"id":2,"questionId":1,"createdDate":"2023-06-04T16:46:52.942835","modifiedDate":"2023-06-04T16:46:52.942835","text":"text","owner":{"id":1,"username":"mickey_m"}},{"id":3,"questionId":1,"createdDate":"2023-06-04T16:46:52.942835","modifiedDate":"2023-06-04T16:46:52.942835","text":"text","owner":{"id":1,"username":"mickey_m"}},{"id":4,"questionId":1,"createdDate":"2023-06-04T16:46:52.942835","modifiedDate":"2023-06-04T16:46:52.942835","text":"text","owner":{"id":1,"username":"mickey_m"}},{"id":5,"questionId":1,"createdDate":"2023-06-04T16:46:52.942835","modifiedDate":"2023-06-04T16:46:52.942835","text":"text","owner":{"id":1,"username":"mickey_m"}}],"count":10}}

Why is that and how do I fix it? Is it because Postgres can’t figure out which id I mean (QuestionComment‘s or Question‘s)? Suggestions?

In case you need to look at the entire project, here’s the repo