mapping 0..1 association

[arvindsj]

Hi,

I was wondering what is the best approach to map an association of the kind where one side is 0..1 and the other is 0..*

I tried using OneToMany annotation along with nullable set to true, but that doesn't work.

Do I have to do this using ManyToMany and provide code to check and enforce that one side does not have more than 1 instance?

Thanks

[alexg79]

I tried using OneToMany annotation along with nullable set to true, but that doesn't work.

Associations are "optional" by default.
To enforce 1..* or 1..1 associations, you'd have to do:
@ManyToOne(optional = false)

What exactly isn't working? Are you using the "mappedBy" property correctly?

Example:

@Entity
public class A {
...
@OneToMany(mappedBy = "myA")
public List<B> getBList() {
 return bList;
}
...
}

@Entity
public class B {
...
@ManyToOne
public A getMyA() {
 return myA;
}
...
}