如何在JPA父实体中将子关联属性用作Map键

在

CarDescription

languageId

@Column(name = "language_id", insertable = false, updatable = false)private Long languageId;@NotNull@OneToOne@JoinColumn(name = "language_id")private Language language;public void setLanguage(Language language) {    this.languageId = language.getId();    this.language = language;}

然后，您可以

Car

@oneToMany(mappedBy="car")@MapKey(name = "languageId")private Map<Long, CarDescription> carDescription = new HashMap<>(0);