Date: Tue, 17 Jul 2012 19:14:19 -0700
Hi,
> I'd like to hear the points of view of the JPA implementations
represented here as to whether
> it would be desirable to strengthen the requirements here or not.
The current spec allows certain flexibility for the implementations to
parse a query during execution as opposed to construction. In OpenJPA, we
prefer such flexibility.
Regards --
Pinaki Poddar
Chair, Apache OpenJPA Project http://openjpa.apache.org/
JPA Expert Group Member
Application & Integration Middleware
From: Linda DeMichiel <linda.demichiel_at_oracle.com>
To: jsr338-experts_at_jpa-spec.java.net
Cc: Oliver Gierke <ogierke_at_vmware.com>, "thomas.hackel_at_gmail.com"
<thomas.hackel_at_gmail.com>
Date: 07/17/2012 02:15 PM
Subject: [jsr338-experts] Re: Ambiguities in exceptions for
EntityManager.createQuery(…)
On 7/17/2012 2:05 AM, Oliver Gierke wrote:
> Hi all,
>
> there are multiple (contradicting) sections in the spec defining the
error cases of EntityManager.createQuery(…). The JavaDoc in 3.1.1 states:
>
>> /**
>> * …
>> * @throws IllegalArgumentException if the query string is
>> * found to be invalid
>> */
>> public Query createQuery(String qlString);
>
> Below the code sample we find the following section:
>
>> If the argument to the createQuery method is not a valid Java
Persistence query string or a valid CriteriaQuery object, the
IllegalArgumentException may be thrown or the query execution will fail and
a PersistenceException will be thrown.
>
> What does "may be thrown" exactly mean? Why is query execution discussed
in this context? Does that mean that createQuery(…) might return a Query
object that will only fail eventually when being executed?
Yes. The provider may defer this check until the point where the query is
to be executed.
If so, why is this allowed actually? If so how can one reliably check a
query string for syntactical correctness?
>
> I currently have code that tries to validate a query string by calling
em.createQuery(…) and catching IllegalArgumentException as defined in the
JavaDoc. Unfortunately I've just discovered Hibernate (3.x and 4.x)
throwing IllegalStateException in case the query tree seems valid in
general but fails being parsed later on.
>
> em.createQuery("somethingAbsurd") -> IllegalArgumentException
> em.createQuery("select disinct(u) from User u") -> IllegalStateException
>
> I'd like to get a clear picture on what is actually required before
filing a ticket against Hibernate. Is it worth to straighten that out in
the upcoming version of the spec?
>
This point was discussed back in the JPA 1.0 days when this decision was
made.
I'd like to hear the points of view of the JPA implementations represented
here as to whether
it would be desirable to strengthen the requirements here or not. For
example, we could
consider adding a query property to indicate that the query string should
be validated early.
-LInda
> Cheers,
> Ollie
>
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