hello,
In my apllication, there are students and classes. a student can take many classes. So there is OneToMany <--> ManyToOne relationship. Im my case, the best implementation is using a join table. I followed examples I found on internet and at books. So I wrote the code (summary) below..

class Class:

@Id
@GeneratedValue
@Column(name="CLASS_ID")
private Integer id;

private String name;

@ManyToOne
@JoinTable(schema="temel", name = "STUDENT_CLASS",
inverseJoinColumns = @JoinColumn(name = "STUDENT_ID", referencedColumnName = "STUDENT_ID"),
joinColumns = @JoinColumn(name = "CLASS_ID", referencedColumnName = "CLASS_ID"))
private Student student;

(Constructor, getters, setters)

class Student:

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "STUDENT_ID")
private Integer id;

private String name;

@OneToMany(mappedBy = "student", cascade=CascadeType.ALL)
private Collection<Class> classes = new ArrayList<Class>();

(Constructor, getters, setters)

because I use "hibernate.hbm2ddl.auto" all tables, including join table, are created. When I push save button, the student and the class data is saved correctly. but there is no information in my join table. I tried many things. I can not find my mistake. I'd appreciate for any help and tips... thanks...

no help??

My hunch is you are not handling the bidirectional association properly.

Please make sure- if you are adding a class for a student (by just adding a class in a list of class for that student), please make sure you also add class to student. Like this

Student s= new Student();
Class c= new Class();

//handle bidirectional relationship
s.getClasses().add(c);
c.setStudent(s);

let me know whether it is working or not.

thank you soooo much. I have been struggling for this problem for 2 weeks. I always thought hibernate would handle bidirectional relation for me. I kept checking my annotations to find out problem.. thanks again for the great support.