Edit primary key, if it's a foreign key

[Hajdu Attila]

I have a problem: I can't know, how edit primary key, if this key is a foreign key...
ER:

I want to edit curseId, but I can't...

User.java

@Entity
@Table(name = "USERS")
public class User implements Serializable
{
  @Id
  @Column(name = "USER_ID", nullable = false, length = 10)
  private String userId;
  @Column(name = "NAME_AT_BIRTH", nullable = false)
  private String nameAtBirth;
  @Column(name = "LAST_NAME", nullable = false)
  private String lastName;
  @Column(name = "FIRST_NAME", nullable = false)
  private String firstName;
  @Column(name = "MOTHERS_NAME", nullable = false)
  private String mothersName;
  @Column(name = "PERM_ADDRESS", nullable = false)
  private String permAddress;
  @Column(name = "TEMP_ADDRESS")
  private String tempAddress;
  @Temporal(value = TemporalType.DATE)
  @Column(name = "BIRTHDATE", nullable = false, length = 7)
  private Date birthdate;
  @Column(name = "PASSWORD", nullable = false, length = 32)
  private String password;
  @Column(name = "EMAIL", length = 320)
  private String email;
  @Temporal(value = TemporalType.DATE)
  @Column(name = "START_DATE", nullable = false, length = 7)
  private Date startDate;
  @Temporal(value = TemporalType.DATE)
  @Column(name = "END_DATE", length = 7)
  private Date endDate;
  @Column(name = "TYPE", length = 16)
  private String type;
  @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "user")
  private List<UserCheck> checks = new ArrayList<UserCheck>();
  @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "user")
  private List<UserCurse> curses = new ArrayList<UserCurse>();
}

Curse.java

@Entity
@Table(name = "CURSES")
public class Curse implements Serializable
{
  @EmbeddedId
  @AttributeOverrides(
  {
    @AttributeOverride(name = "curseId", column = @Column(name = "CURSE_ID", nullable = false, length = 16)),
    @AttributeOverride(name = "semesterId", column = @Column(name = "SEMESTER_ID", nullable = false, length = 10))
  })
  private CurseId id;
  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumn(name = "SEMESTER_ID", nullable = false, insertable = false, updatable = false)
  private Semester semester;
  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumn(name = "ROOM_ID", nullable = true)
  private Room room;
  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumn(name = "SUBJECT_ID", nullable = false)
  private Subject subject;
  @Column(name = "TIME", nullable = true, length = 32)
  private String time;
  @Column(name = "STUDENTS_LIMIT", precision = 10, scale = 0, nullable = true)
  private Long studentsLimit;
  @OneToOne
  @JoinColumns(value =
  {
    @JoinColumn(name = "CURSE_ID", referencedColumnName = "CURSE_ID", nullable = false, insertable = false, updatable = false),
    @JoinColumn(name = "SEMESTER_ID", referencedColumnName = "SEMESTER_ID", nullable = false, insertable = false, updatable = false)
  })
  private CurseUserCountView curseUserCountView;
  @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "curse")
  private List<UserCurse> users = new ArrayList<UserCurse>();
  @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "curse")
  private List<Check> checks = new ArrayList<Check>();
}

CurseId.java

@Embeddable
public class CurseId implements Serializable
{
  @Column(name = "CURSE_ID", nullable = false, length = 16)
  private String curseId;
  @Column(name = "SEMESTER_ID", nullable = false, length = 10)
  private String semesterId;
}

UserCurse.java

@Entity
@Table(name = "USERS_CURSES")
public class UserCurse implements Serializable
{
  @EmbeddedId
  @AttributeOverrides(
  {
    @AttributeOverride(name = "userId", column = @Column(name = "USER_ID", nullable = false, length = 16)),
    @AttributeOverride(name = "curseId", column = @Column(name = "CURSE_ID", nullable = false, length = 16)),
    @AttributeOverride(name = "semesterId", column = @Column(name = "SEMESTER_ID", nullable = false, length = 10))
  })
  private UserCurseId id;
  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumn(name = "USER_ID", nullable = false, insertable = false, updatable = false)
  private User user;
  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumns(value =
  {
    @JoinColumn(name = "CURSE_ID", referencedColumnName = "CURSE_ID", nullable = false, insertable = false, updatable = false),
    @JoinColumn(name = "SEMESTER_ID", referencedColumnName = "SEMESTER_ID", nullable = false, insertable = false, updatable = false)
  })
  private Curse curse;
  @Column(name = "PERFORMED", precision = 1, scale = 0)
  private Boolean performed;
}

UserCurseId.java

@Embeddable
public class UserCurseId implements Serializable
{
  @Column(name = "USER_ID", nullable = false, length = 16)
  private String userId;
  @Column(name = "CURSE_ID", nullable = false, length = 16)
  private String curseId;
  @Column(name = "SEMESTER_ID", nullable = false, length = 10)
  private String semesterId;
}

Thanks for helping!

[David Newton]

(Off-topic: are you keeping a list of the swear words the students use? ;) It's "course", not "curse" :)

[Hajdu Attila]

David Newton wrote:(Off-topic: are you keeping a list of the swear words the students use? ;) It's "course", not "curse" :)

Thank you for your comments! It's meaning course, of course :mrgreen:
OFF: My university have "NEPTUN" web based education system, and theme of my thesis is a same system. In NEPTUN, it's "curse"...

[James Sutherland]

What do you mean by "edit", update?

You cannot update a primary key. You should delete the UserCurse object, and add a new one to the different Curse.

For an insert, you can just create the new UserCurse and set its Id.

[Hajdu Attila]

James Sutherland wrote:What do you mean by "edit", update?

Simple update courseId, for example...

Curse curse = curseDao.find(new CurseId("old", "2010"));
curse.setId(new CurseId("new", "2010"));
curseDao.update(curse);

Before:
Curses
curse_id semester_id ....
old 2010
old2 2010

Users_curses
curse_id semester_id user_id ...
old 2010 shark300

After:
Curses
curse_id semester_id ....
new 2010
old2 2010

Users_curses
curse_id semester_id user_id ...
new 2010 shark300

Any idea for editing Curse entity?

[Paul Sturrock]

As James points out, editing a primary key == inserting a new record. So I'd do what he's already suggested, delete the existing records and a a new one.

[Hajdu Attila]

Course course = courseDao.findById(new CourseId(courseId, semesterId), false);
List<Check> checks = course.getChecks();
List<UserCourse> users = course.getUsers();

Course newCourse = new Course(new CourseId("modifiedCourseId", semesterId), course.getSemester(), course.getSubject(), course.getRoom(), course.getStudentsLimit(), course.getTime());

courseDao.getSession().evict(course);
newCourse.setChecks(checks);
newCourse.setUsers(users);

courseDao.create(newCourse);
//      courseDao.delete(course);

This code don't create row in Users_Course... I know, if I create some new instances of UserCourse with "modifiedCourseId" courseId, rows are created.
But if this row is edited, I have to edit all instance in database, where courseId is "sub-primary key".

Any idea for editing Curse entity?

[Paul Sturrock]

What is a "sub-primary" key?

[Hajdu Attila]

Paul Sturrock wrote:What is a "sub-primary" key?

courseId is a element of multiple primary key of Checks table.

Check.java

@Entity
@Table(name = "CHECKS")
public class Check implements Serializable
{
  @EmbeddedId
  @AttributeOverrides(
  {
    @AttributeOverride(name = "courseId", column = @Column(name = "COURSE_ID", nullable = false, length = 16)),
    @AttributeOverride(name = "checkDate", column = @Column(name = "CHECK_DATE", nullable = false, length = 7)),
    @AttributeOverride(name = "semesterId", column = @Column(name = "SEMESTER_ID", nullable = false, length = 10))
  })
  private CheckId id;
  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumns(value =
  {
    @JoinColumn(name = "COURSE_ID", referencedColumnName = "COURSE_ID", nullable = false, insertable = false, updatable = false),
    @JoinColumn(name = "SEMESTER_ID", referencedColumnName = "SEMESTER_ID", nullable = false, insertable = false, updatable = false)
  })
  private Course course;
  @Column(name = "TYPE",  nullable = true, length = 16)
  private String type;
  @Column(name = "STUDENTS_LIMIT", precision = 10, scale = 0, nullable = true)
  private Long studentsLimit;
}

CheckId.java

@Embeddable
public class CheckId implements Serializable
{
  @Column(name = "COURSE_ID", nullable = false, length = 16)
  private String courseId;
  @Column(name = "CHECK_DATE", nullable = false, length = 7)
  @Temporal(TemporalType.TIMESTAMP)
  private Date checkDate;
  @Column(name = "SEMESTER_ID", nullable = false, length = 10)
  private String semesterId;
}