TopLink JPA join problems.

Question

I need a bit of help here, I hope someone can give me a few pointers...
I've been building out an Object Relational mapping in TopLink using the bean-style interfaces. On one of my objects I have a 1:M relationship to another table, so
One Key in T1 -> >1 Keys in T2.
Pretty simple really. I'm doing it like this:
@JoinTable( name=, etc. etc.)
private Set<ObjectForTable2> variableName.
When I call the getVariableName() method, I get back an IndirectSet (as a set) from the method as expected; however, the size of this set is either 0 or 1.
In Table 2 I have approximately a dozen rows which correspond to the join key, and when I run the query toplink is building in my SQL shell, I get back the dozen rows. When TopLink does it, I only get to see the first row. Is there some other trick I need to use with the set returned? Right now when I call mySet.size() on the Set returned from getVariableName() I get a size of 1 or 0. (I only get 0 if I change the key to one that does not exist in table 2.)
if I use the iterator method, such as
for ( final Iterator i = mySet.iterator(); i.hasNext(); ) {
ObjectForTable2 myObj = (ObjectForTable2)i.next();
System.out.println( myObj.getXXX() );
I still only get one result out. Help! What am I doing wrong here? Do I need to configure something to pull back more than one record from the database?
Also, how does one use the Oracle bugtracker for this open-source product, if I don't have a service contract?
Thanks,
Robbie

Answer 1

Exactly.
In TopLink (and in JPA in general) you need identify the field, or combination of fields that are used to uniquely identify entities. As Doug mentioned, it is most common that these fields are the PK of the database.
Based on your response above I assume that you had a non unique field mapped as the PK of the enitity. This could cause the trouble you are experiencing. Mapping the pk to a unique field (or combination of fields) will likely solve this problem.