@JoinColumn(columnName) - specify foreign key column name to join other entity's by its primary key - for @OneToOne relation.
@JoinColumn or @JoinColumn() - foreign key column name will be autogenerated from referenced entity name, with _fk suffix.
This annotation is mandatory if property has @OneToOne annotation w/o parameter or @ManyToOne annotation
@JoinColumn(columnName) - specify foreign key column name to join other entity's by its primary key - for @OneToOne relation. @JoinColumn or @JoinColumn() - foreign key column name will be autogenerated from referenced entity name, with _fk suffix. This annotation is mandatory if property has @OneToOne annotation w/o parameter or @ManyToOne annotation