Re: [eclipselink-users] Creation of M-M-Relation/Association fails

[Michael Simons <michael.simons@xxxxxxxxxxx>]

Hello Tom,

please, forget it. It's my fault. I filled only the top-right triangle of the matrix, but had
overseen that this special compatibility is symetric. So I must also fill the bottom-left half
of the matrix, or only read the top-right one.
As we use the same matrix for non-symetric compatibilities I will do it the first way.

Thanks a lot, Michael

Tom Ware schrieb:
> Hi Michael,
> 
>   A few more questions.
> 
> 1. What do line.removeCompatibleProducts (obsoletes) and
> line.addCompatibleProducts (news) do?
> 
> 2. Is it possible that obsoletes and news contain the same data?
> 
> 3. Is it possible to get a sample output with logging set to FINEST?
> 
> -Tom
> 
> Michael Simons wrote:
>> Hello Tom,
>>
>> As the code runs within a standalone application, the entity manager
>> is created
>> (emf.createEntityManager()) at the start and closed when the app
>> terminates.
>> I get the transaction using em.getTransaction()
>> The code that persists the entities is attached (excerpt.java)
>>
>> Kind Regards, Michael
>>
>> Tom Ware schrieb:
>>> Hi Michael,
>>>
>>>   What is the actual code you are running?  (i.e. how do you get your
>>> entity manager, what does the code that persists your objects look
>>> like?  how are you getting your transactions?)
>>>
>>> -Tom
>>>
>>> Michael Simons wrote:
>>>> Hello,
>>>>
>>>> I've got an Entity class Product with a self-relation:
>>>>     /** Set of products this one is compatible with.*/
>>>>     @ManyToMany(fetch=FetchType.LAZY, cascade={CascadeType.PERSIST,
>>>> CascadeType.REFRESH})
>>>>     @JoinTable(name="product_product_compatibility",
>>>>         joinColumns={@JoinColumn(name="prev_product_id")},
>>>>         inverseJoinColumns={@JoinColumn(name="next_product_id")})
>>>>     private Set<Product> compatibleProducts = new HashSet<Product>();
>>>>
>>>> Guess what happens when I add products to this set like this:
>>>>     public boolean addCompatibleProduct (Product product) {
>>>>         if (compatibleProducts == null)
>>>>             compatibleProducts = new HashSet<Product>();
>>>>         boolean added = compatibleProducts.add (product);
>>>>         if (added)
>>>>             product.addCompatibleProduct (this);
>>>>         return added;
>>>>     }
>>>>
>>>> If you said nothing, you've won. The only SQL that was generated is:
>>>> [EL Fine]: 2010-03-15
>>>> 15:48:09.88--ClientSession(5978600)--Connection(23637841)--Thread(Thread[main,5,main])--UPDATE
>>>>
>>>>
>>>> product SET jdo_version = ? WHERE ((product_id = ?) AND (jdo_version =
>>>> ?))
>>>>     bind => [43, 30, 42]
>>>> [EL Fine]: 2010-03-15
>>>>
>>>> What can I do to avoid this? Or is this a bug of EclipseLink?
>>>>
>>>> Kind Regards, Michael
>>>> _______________________________________________
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>>
>>
>>
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