Hello Patrick,
thank you very much for your answer! I expected some part of the spec
would throw a monkey wrench in my plan, but your solution is of great
help! Now i can work around the missing functionality.
With best regards,
Daniel Migowski
Patrick Linskey schrieb:
Hmm. So I think that the spec is clear that you'd get an
outer join if
you had done something like:
select c from Company c
where c.lastModifiedBy.username = :name or c.lastModifiedBy is
null
and that you'd get an inner join if you did:
select c from Company c
where c.lastModifiedBy.username = :name
However, in your case, you're only using the path _expression_ in the
SELECT clause. I think that section 4.4.4 of the spec is the problem
here:
"Path _expression_ navigability is composed using "inner join"
semantics. That is, if the value of a non-terminal association-field
in the path _expression_ is null, the path is considered to have no
value, and does not participate in the determination of the result."
Applied to the context of a query that has no WHERE clause, this is
what's causing the behavior you're seeing.
I think that an explicit join should do the trick:
select c.id, user.username from Company c left join c.lastModifiedBy
user
-Patrick
On 7/5/07, Daniel Migowski <[EMAIL PROTECTED]> wrote:
Hi Patrick,
thank you for your reply. My persistence.xml list the company and the
user:
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
version="1.0">
<persistence-unit name="none"
transaction-type="RESOURCE_LOCAL">
<class>de.ikoffice.model.EntityBase</class>
...
<class>de.ikoffice.app.core.model.Company</class>
...
<class>de.ikoffice.app.core.model.User</class>
</persistence-unit>
<!-- persistence unit for IKOffice -->
<persistence-unit name="ikoffice"
transaction-type="RESOURCE_LOCAL">
<class>de.ikoffice.model.EntityBase</class>
...
<class>de.ikoffice.app.core.model.Company</class>
...
<class>de.ikoffice.app.core.model.User</class>
</persistence-unit>
</persistence>
In Company.java I have the following definition:
@ManyToOne(cascade=CascadeType.PERSIST)
User lastModifiedBy;
Any ideas?
With best regards,
Daniel Migowski
Patrick Linskey schrieb:
> Hi,
>
> Can you post your persistence.xml and Company.java?
> Generally-speaking, I believe that you should see an outer join if
> your model is configured accordingly.
>
> -Patrick
>
> On 7/5/07, Daniel Migowski <[EMAIL PROTECTED]> wrote:
>>
>> Hello OpenJPA users,
>>
>> if have the following OpenJPA query. It gets all company-ids
and for
>> the
>> companies having a lastmodifiedby-user, it should return the
username:
>>
>> select c.id, c.lastModifiedBy.username from Company c
>>
>> The resulting native query is:
>>
>> SELECT t0.id, t1.username FROM Company t0 INNER JOIN dbuser
t1 ON
>> t0.lastModifiedBy_id = t1.id
>>
>> This one does an inner join on the dbuser table, but i need
to fetch
>> the
>> records by a left join. In my opinion, the left join should be
>> default on
>> relation traversial operations, because then you could easiely
have the
>> other behavoiur with a simple "WHERE c.lastModifiedBy IS NOT
NULL".
>> With the
>> current behaviour i have to do UNION-SELECTs if i just want to
have
>> every
>> field. Is there a way to change this behaviour?
>>
>> Greetings,
>> Daniel Migowski
>>
--
|¯¯|¯¯| IKOffice GmbH Daniel Migowski
| | |/| Mail: dmigowski at ikoffice.de
| | // | Nordstr. 10 Tel.: +49 (441) 21 98 89 52
| | \\ | 26135 Oldenburg Fax.: +49 (441) 21 98 89 55
|__|__|\| http://www.ikoffice.de Mob.: +49 (176) 22 31 20 76
Geschäftsführer: Ingo Kuhlmann, Daniel Migowski
Amtsgericht Oldenburg, HRB 201467
--
|¯¯|¯¯| IKOffice GmbH Daniel Migowski
| | |/| Mail: [EMAIL PROTECTED]
| | // | Nordstr. 10 Tel.: +49 (441) 21 98 89 52
| | \\ | 26135 Oldenburg Fax.: +49 (441) 21 98 89 55
|__|__|\| http://www.ikoffice.de Mob.: +49 (176) 22 31 20 76
Geschäftsführer: Ingo Kuhlmann, Daniel Migowski
Amtsgericht Oldenburg, HRB 201467
Steuernummer: 64/211/01864
|
