@Transient can't get data from Entity

In my project, in the repository, I have a select that displays all the data I need, including those months for which I don’t have data. To do this, in my select, I create a temporary column, which I named tneDate .

@Query(value = "SELECT \n" +
            "  theDate, asl.id, asl.interest_payment, asl.interest_rate, asl.principal_payment, asl.total_payment, asl.actual_delta, \n" +
            "  asl.date, asl.modified, asl.interest_payment_modified, asl.amortization_schedule_initial_id, asl.tranche_id, asl.outstanding_usd,\n" +
            "  asl.disbursement, asl.floating_index_rate, asl.upfront_fee, asl.commitment_fee, asl.other_fee, asl.withholding_tax, \n" +
            "  asl.default_fee, asl.prepayment_fee, asl.total_out_flows, asl.net_flows, asl.user_id, asl.outstanding_principal, asl.new_row\n" +
            "FROM\n" +
            "  GENERATE_SERIES\n" +
            "  (\n" +
            "    (SELECT MIN(ams.date) FROM amortization_schedules ams),\n" +
            "    (SELECT MAX(ams.date) + INTERVAL '1' MONTH FROM amortization_schedules ams),\n" +
            "    '1 MONTH'\n" +
            "  ) AS tab (theDate)\n" +
            "FULL JOIN amortization_schedules asl on to_char(theDate, 'yyyy-mm') = to_char(asl.date, 'yyyy-mm')", nativeQuery = true)
    List<AmortizationSchedule> findAllByDate();

Now, through the getter in Entity , I want to get only this tneDate , that is, the date that I form. I don't want it to be written to the database. Therefore, I put the @Transient annotation, but as I understand it, this annotation ignores the getter of this entity and I cannot get this data, since I get NULL. In this part :

else {
                        BigDecimal swaprate = getRate(previousAmortiz.getDate(), previousAmortiz.getTranche().getLocalCurrency().getId());
                        childReports.add(createChild(previousAmortiz.getOutstandingPrincipal(), swaprate, previousAmortiz.getTheDate()));

My Entity

@Getter
@Setter
@ToString
@Entity
@Table(name = "amortization_schedules")
public class AmortizationSchedule {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;

    @Transient
    private Date theDate;

    @Column(name = //)
    private BigDecimal //;

how do i get the tneDate data?