hibernate一对一，一对多更新语句问题

object references an unsaved transient instance - save the transient instance before flushing: com.SelectCourseSystem.pojo.Student
三个类，一个StudentUser，一个Student，一个StudentCourse，其中StudentUser与Student是一对一关系（单向），Student与StudentCourse是一对多关系（单向关联表）现在执行跟新语句出现上面的问题
@Entity
@Table(name="t_studentuser")
public class StudentUser {
private int id;
private String username;
private String password;
private Student student;
......
@OneToOne(cascade=CascadeType.ALL)
@JoinColumn(name="studentId")
public Student getStudent() {
return student;
}
...
}
@Entity
@Table(name="t_student")
public class Student {
private int id;
private String name;
private int age;
private String sex;
private String specialty;
private List courses;
....
@OneToMany(cascade=CascadeType.ALL,fetch=FetchType.LAZY)
@JoinTable(
name="CourseForStudent",
joinColumns = @JoinColumn( name="studentid"),
inverseJoinColumns = @JoinColumn( name="studentcourseid")
)
public List getCourses() {
return courses;
}
....
}
测试类
public void testUpdateStudentUser() {
Configuration configuration = new AnnotationConfiguration().configure();
SessionFactory sessionFactory = configuration.buildSessionFactory();
Session session = null;
Transaction transaction = null;
Query query=null;
int i=0;
try {
session = sessionFactory.openSession();
transaction=session.beginTransaction();
String hql="update StudentUser as s set s.username=?,s.password=?,s.student=? where s.id =?";
query=session.createQuery(hql);
List courses=new ArrayList();
StudentCourse course01=new StudentCourse("math", "xsyuBbuilding", "xiaoming");
StudentCourse course02=new StudentCourse("physical", "xsyuBbuilding", "lihua");
StudentCourse course03=new StudentCourse("biological", "xsyuBbuilding", "xiaohua");
courses.add(course01);
courses.add(course02);
courses.add(course03);
Student student=new Student("zhouhouyu", 21, "man", "physical", courses);
query.setString(0, "201401020133");
query.setString(1, "020133");
query.setParameter(2, student);
query.setInteger(3, 1);
i=query.executeUpdate();
transaction.commit();
} catch (Exception e) {
e.printStackTrace();
transaction.rollback();
} finally {
session.close();
System.out.println(i);
}
}
小白求教

Student student=new Student("zhouhouyu", 21, "man", "physical", courses);
如果这个是新添加的记录，先要调用save保存，如果是已经存在的，不应该new,而是应该查询出来