Well CONNECT BY is just a special syntax for recursive CTEs as far as I
am aware. Recursive and updateable CTEs are supported by Oracle, DB2,
MSSQL, PostgreSQL and partially by H2.
Regards,
Christian
Am 26.01.2016 um 17:51 schrieb Paul Benedict:
> Christian, I am only aware of Oracle using CONNECT BY. Are there other
> database vendors that support this? If it's only one vendor, I am not
> sure a general JPA solution is appropriate; but that's going to be
> based on your researched answer.
>
> Cheers,
> Paul
>
> On Tue, Jan 26, 2016 at 10:45 AM, Christian Beikov
> <christian.beikov_at_gmail.com <mailto:christian.beikov_at_gmail.com>> wrote:
>
> No I didn't mention this to the JPA spec lead yet. I wanted to
> create a POC first and get feedback from the Hibernate team before
> actually discussing standardization within JPA.
> As you already mentioned, there are many RDBMS vendors that simply
> don't or just partially support CTEs. At the moment the library
> fails with an exception if a feature that you use isn't supported
> by the RDBMS.
>
> I don't have full EclipseLink support yet but I'd be happy to
> implement it with some help.
>
> Regards,
> Christian
>
> Am 26.01.2016 um 13:34 schrieb Heiko Wagner:
>>
>> Hello Christian,
>>
>> thanks for your reply. Glad to hear that I am not the only one
>> with this problem. Did you already approach the JPA spec
>> lead/team, what they think about adding CTE query support to
>> JPAQL? I know that current RDBMS support for CTEs strongly varies
>> among the different vendors, which makes implementing a proper
>> portable abstraction a real pain.
>>
>> I will take a closer look at your project soon. I am currently
>> using EclipseLink. From the quick look at the github page, I am
>> assuming there is also support for EclipseLink?
>>
>> Regards,
>>
>> Heiko
>>
>> Am 2016-01-26 12:36, schrieb Christian Beikov:
>>
>>> Hello,
>>>
>>> I had the same problem as you did, missing support for CTEs.
>>> That's one reason why I created blaze-persistence[1 <https://github.com/Blazebit/blaze-persistence>] which implements support for CTEs for Hibernate.
>>>
>>> Hope this library can help you to ease your pain in the meantime until JPA gets these features.
>>>
>>> Regards,
>>> Christian
>>>
>>> [1]https://github.com/Blazebit/blaze-persistence
>>>
>>> Am 26.01.2016 um 10:33 schriebheiko.wagner_at_apis.de: <mailto:heiko.wagner_at_apis.de:>
>>>> Hi, I am currently working on a proof of concept Java SE
>>>> application. I am using JPA for persintence, since I am
>>>> faliliar with it from my Java EE project. I am trying to find
>>>> out what would be a good solution to store directed acyclic
>>>> object graphs. As far as I found out, there is no abstraction
>>>> support for "CONNECT BY" / recursive CTEs in JPA. I could
>>>> resort back to using native queries or drop JPA entirely in
>>>> favour of a graph oriented db. Are there any condierations of
>>>> providing support in JPA for this in the future?
>
>