problem in bidirectional one to many associations

[pollux]

Hi,

I have a couple of many to one relationships that involve more than two classes.

For example:

1 Project <-> many Resource
1 Project<-> many Partner

Project contains the fields

@NotNull
private Integer id;

@OneToMany(cascade = CascadeType.ALL, mappedBy = "project")
private Set<Resource> resources = new HashSet<Resource>();

@OneToMany(cascade = CascadeType.ALL, mappedBy = "project")
private Set<Partner> partners = new HashSet<Partner>();


Resource contains the fields

@NotNull
private Integer id;

@ManyToOne(targetEntity = Project.class)
@JoinColumn(name = "id")
private Project project;


and Partner contains the fields

@NotNull
private Integer id;

@ManyToOne(targetEntity = Project.class)
@JoinColumn(name = "id")
private Project project;



when I run the tests, I get the following exception (root cause only, not the full stacktrace):

...
Caused by: org.hibernate.MappingException: Repeated column in mapping for entity: com.mycompany.myproject.domain.Partner column: id (should be mapped with insert="false" update="false")
...



When I change the ManyToOne mappings as follows, tests are OK:


@ManyToOne(targetEntity = Project.class)
@JoinColumn(name = "id", insertable = false, updatable = false)
private Project project;


I think these properties are required when two child entities reference the same parent through the same ID field.

Has this been left intentionally like this, or is it a bug?

Thank you for your help

Kind Regards,

Raul

[Stefan Schmidt]

This seems to be more of a JPA configuration issue. I believe you need to use @ManyToMany (available with the --cardinality attribute in the Roo shell command). Maybe you can share your complete script so we can help with it.

Cheers,
Stefan