springmvc+hibernate在实体类中设置外键

1.表User id主键，username,password,dept...

表Attendence id主键，uid外键，time...

 @ManyToOne
     @JoinColumn(name = "uid",referencedColumnName="id")
     private User user;

     public User getUser() {
         return user;
     }

     public void setUser(User user) {
         this.user = user;
     }

2.查询时只需  u.user.id即可