Hibernate query returns null, but entity gets loaded on object anyway

Question

This will take some explaining. So, I have an entity called Invoice and a related table called Errors, which is used to store some processing errors.

In a DAO class, I have a query for fetch the errors with some specific criteria:

public Errors loadLastError(Invoice i) {
        try (Session session = factory.openSession()) {
            Query query = session.createQuery("select er from Errors er" +
                    " inner join er.invoice i" +
                    " where er.invoice = :invoice" +
                    " and i.status <> :code" +
                    " and i.proccessStatus = :status" +
                    " order by er.id desc");
            query.setParameter("invoice", invoice);
            query.setParameter("code", "001");
            query.setParameter("status", "form_error");
            var result = query.getSingleResult();
            return (Errors) result;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

This works fine: will only get results when the conditions match. When they don't, I get the expected null result where this method is called:

this.invoice.setError(loadLastError(this.invoice);

When inspecting the code, I can see that the this.invoice object was updated correctly with a null result.

But, as soon as I pass this object invoice to another class in order to do some proccessing (send notifications basically by JSON), it gets there with a Errors object loaded, as if my original query had actually found something, which it didn't.

The following are a shortened example of my entity classes:

The Invoice:

@Entity
@DynamicUpdate
@Table(name = "data.invoice")
@TypeDef(
        name = "pgsql_enum",
        typeClass = PostgreSQLEnumType.class
)
public class Invoice implements Serializable {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;

@JsonIgnore
@Column(name = "proccessStatus")
private String proccessStatus;

@JsonIgnore
@Column(name = "status")
private String status;

@JsonIgnore
@OneToOne(mappedBy = "invoice", fetch = FetchType.LAZY)
private Errors errors;

    public Integer getId() {
        return id;
    }

    public String getProccessStatus() {
        return proccessStatus;
    }

    public void setProccessStatus(String proccessStatus) {
        this.proccessStatus= proccessStatus;
    }

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status= status;
    }

    public Errors getErrosr() {
        return errors;
    }

public void setErrors(Errorserrors) {
        this.errors= errors;
    }

The Errors entity:

@Entity
@Table(name = "data.invoice_errors")
public class Errors implements Serializable {

    public Errors() {
    }

    public Errors(Invoice invoice, String error) {
        this.invoice= invoice;
        this.error = error;
    }

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @OneToOne
    @JoinColumn(name = "id_invoice")
    private Invoice invoice;

    private String error;

    @Column(name = "created_at")
    private LocalDateTime createdAt;

    public Integer getId() {
        return id;
    }

    public Invoice getInvoice() {
        return invoice;
    }

    public void setInvoice(Invoice invoice) {
        this.invoice = invoice;
    }

    public String getError() {
        return error;
    }

    public void setError(String error) {
        this.error = error;
    }

    public LocalDateTime getCreatedAt() {
        return createdAt;
    }

This behaviour seems very strange and I don't know how to diagnose it and what may be wrong. Any input would be very appreciated.

What I'm expecting is that the entity don't get updated out of nowhere with a result that wasn't found initially because it simply didn't match the search criteria in the first place.

Answer 1

I'm a colossal idiot. The issue was that the notification class was refreshing the model. Changed the database search to go after the refresh and fixed the problem.