Hi,

I'm using hibernate 3.3.1.GA with annotation 3.4.0.GA to access a local mysql database. Currently I also use hibernate to create/update my database during program startup by setting the "hibernate.hbm2ddl.auto" property to "update". But unfortunately I have some objects which use only the Integer or Long primary key to reference an associated object - e.g.


Unfortunately I'm unable to create forein key constraints in the database this way since a possible @ForeignKey annotation is ignored.
However I'm able to let hibernate create the foreign key constraint if I change the annotations like follows:



However this causes write and/or read accesses to the B table to fail with a "java.lang.IllegalArgumentException: object is not an instance of declaring class". Hibernate seems to try to the set id property of the A class on a primitive of the type int.

So I wonder if there is any way to cause hibernate to create foreign key constraints without having to use full Object references in the object model. (To have B reference a lazy loaded instance of A is not an option because the object is serialized and sent to other machines).

I found out that adding a lazy loaded Set to class A will enable me to add a @JoinColumn(name = "a_id") annotation to this set which will result in the foreign key to be creted in the table of b - but this is kind of clumsy and smells like a Hack since this collection is never needed/read and further I have to add an annotation to class A to modify the table of class B - not really obvious.

Just for the case someone should be interested: I solved the problem in the end by adding an own "ForeignKey" annotation that can be added to any column/field. To apply it I overloaded the AnnotationConfiguration used - all I had to do is overloading the secondPassCompile() method and parse all table classes for my annotation after the super method was invoked.
I simply invoked the Table.createForeignKey() method for all annotated columns.

Perhaps such an annotation could be usefull in the hibernate-annotation package as well? Of course one would have to check more closely if the key would be valid than I did it to solve my problem.