yet another question about Hibernate lazy loading not working, but this time I have done my research beforehand.

From what I understood from Hibernate docs and so many other posts here on SO, on Hibernate 6.4 the @ManyToOne with FetchType.LAZY should work on the owning side, and that’s what I have. This is my entity:

public final class Club {
    @Id
    private UUID id;

    @Column(name = "name", nullable = false)
    private String name;

    @Column(name = "abbreviation", nullable = false)
    private String abbreviation;

    @Column(name = "crest", columnDefinition = "jsonb")
    @Type(JsonBinaryType.class)
    private Crest crest;

    @Column(name = "is_bot", nullable = false)
    private boolean isBot;

    @ManyToOne(optional = false, fetch = FetchType.LAZY)
    @JoinColumn(name = "country_id", nullable = false)
    private Country country;

    @OneToOne(optional = false, fetch = FetchType.LAZY)
    @JoinColumn(name = "region_id", nullable = false)
    private Region region;

    @ManyToOne(optional = false, fetch = FetchType.LAZY)
    @JoinColumn(name = "league_id", nullable = false)
    private League league;
}

The relationships are mandatory and from what I’ve seen using the parameter optional = false together with fetch = FetchType.LAZY should do the trick to lazily load the relationships, but that’s not happening. On the other side of the relationship – just to be sure – I’m also adding the fetch = FetchType.LAZY even though on @OneToMany the default is to lazy load.

public final class Country {
    @Id
    private UUID id;

    @Column(name = "international_name", nullable = false)
    private String internationalName;

    @Column(name = "name", nullable = false)
    private String name;

    @Column(name = "code", nullable = false)
    private String code;

    @Column(name = "language", nullable = false)
    private String language;

    @Column(name = "timezone", nullable = false)
    private String timezone;

    @Column(name = "flag", nullable = false)
    private String flag;

    @Column(name = "match_date_times", columnDefinition = "jsonb", nullable = false)
    @Type(JsonBinaryType.class)
    private Map<MatchDate.MatchDateType, List<MatchDay>> matchDateTimes;

    @OneToMany(mappedBy = "country")
    private List<Region> regions;

    @Column(name = "enabled", nullable = false)
    private boolean enabled;

    @OneToMany(mappedBy = "country", fetch = FetchType.LAZY)
    private List<Club> clubs;
}

Am I missing something here?

I’m using Spring Boot 3.2.2 and Hibernate 6.4.1.Final.

Thanks for your help.