Many-to-Many relationship problem
when i add a collection to one side of the many-to-many relationship it doesn't add it to the other side.
ex. A test has many multiple choice questions, and multiple choice question can belong to many tests(makes creating a final exam easier, so you can use old questions)
relevant tables:
test(id, testName, courseid)
test_mcquestion(testid, mcquestionid) - both foreign keys to respective tables
mcquestion(id, question, optionA....optionE, answer)
here are the entity beans that netbeans created, i think there is something wrong with the many-to-many mapping...
@Entity
@Table(name ="test")
publicclass Testimplements Serializable{
@Id
@Column(name ="id", nullable =false)
private Integer id;
@Column(name ="testName", nullable =false)
private String testName;
@ManyToMany(mappedBy ="testidCollection")
private Collection<Essay> essayidCollection;
@ManyToMany(mappedBy ="testidCollection", fetch=FetchType.EAGER)
private Collection<Mcquestion> mcquestionidCollection;
@ManyToMany(mappedBy ="testidCollection")
private Collection<Truefalse> truefalseidCollection;
@JoinColumn(name ="courseID", referencedColumnName ="id")
@ManyToOne
private Course courseID;
...appropriate setters & getters....
@Entity
@Table(name ="mcquestion")
publicclass Mcquestionimplements Serializable{
@Id
@Column(name ="id", nullable =false)
private Integer id;
@Column(name ="question", nullable =false)
private String question;
@Column(name ="optionA", nullable =false)
private String optionA;
@Column(name ="optionB", nullable =false)
private String optionB;
@Column(name ="optionC", nullable =false)
private String optionC;
@Column(name ="optionD", nullable =false)
private String optionD;
@Column(name ="optionE", nullable =false)
private String optionE;
@Column(name ="answer", nullable =false)
private String answer;
@JoinTable(name ="test_mcquestion", joinColumns ={
@JoinColumn(name ="mcquestionid", referencedColumnName ="id")
}, inverseJoinColumns ={
@JoinColumn(name ="testid", referencedColumnName ="id")
})
@ManyToMany
private Collection<Test> testidCollection;
...appropriate setters & getters....
code to create mcquestion.....
Mcquestion newmc =new Mcquestion();
newmc.setQuestion(request.getParameter("question"));
newmc.setOptionA(request.getParameter("optionA"));
newmc.setOptionB(request.getParameter("optionB"));
newmc.setOptionC(request.getParameter("optionC"));
newmc.setOptionD(request.getParameter("optionD"));
if(request.getParameter("optionE") !=null){
newmc.setOptionE(request.getParameter("optionE"));
}
ArrayList<Test> newcoll =new ArrayList<Test>();
newcoll.add(testFacade.find(Integer.parseInt(request.getParameter("testID"))));
newmc.setTestidCollection(newcoll);
newmc.setAnswer(request.getParameter("answer"));
mcquestionFacade.create(newmc);
any help would be greatly appreciated
