Hibernate执行插入而非更新的问题排查求助

最近我在用Hibernate开发一款音乐管理系统，先贴出核心的两个实体类代码：

Song 实体类 #

@Entity
@Table(name = "Song")
public class Song implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    private String title;
    
    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "artist_id")
    private Artist artist;
}

Artist 实体类 #

@Entity
@Table(name = "Artist")
public class Artist implements Serializable{
    @Id
    @GeneratedValue(strategy = G...
}

内容的提问来源于stack exchange，提问作者clorisanderton