Thanks for all the input. I've created a NetBeans issue:
http://www.netbeans.org/issues/show_bug.cgi?id=81716
Cheng
Craig L Russell wrote:
> Hi Cheng,
>
> On Aug 1, 2006, at 12:29 PM, Cheng Fang wrote:
>
>> Thanks, Gordon. I've posted your reply to the forum. I also tried
>> this usecase on Toplink/Hibernate + J2SE, and it does work.
>>
>> Now the question from the user is, NetBeans 5.5 beta 2 does not
>> support entity class generation from tables with no primary key. In
>> the generate-entity-class-from-table wizard, all tables with no
>> primary key are grayed out.
>>
>> Why would NetBeans disable a feature supported by Glassfish, Toplink
>> and Hiberante? Can we enable it?
>
>
> I was one of the people with input to the original design decision (5
> years ago) to disallow generation of persistent classes where there
> was no primary key column in the table. We did not try to guess if
> the user intended that one of the unique constraints was supposed to
> map to an identity field.
>
> As I understand it, during generation of the class, the wizard needs
> additional user input or needs to take a guess as to which unique
> constraint should map to @Id. It's not clear what a rational default
> should be in the case that there are multiple unique constraints that
> might be mapped. And since the Id field is immutable after persist,
> it's not clear that you would have a usable class by mapping such a
> table.
>
> A feature in the wizard to guess the Id of a table without a primary
> key can be added but wasn't part of the original design specification.
>
> I'd suggest filing a feature request in Glassfish/Netbeans so we can
> track it formally.
>
> Regards,
>
> Craig
>
>>
>> Cheng
>>
>>
>>
>>
>> Gordon Yorke wrote:
>>
>>> Hello Cheng,
>>> If they know which columns correspond to the Unique Index they can
>>> map these as the PK's in EJB3 even though they are not specified as
>>> PK's in their tables. These @Id mappings would satisfy the EJB3.0
>>> requirements but their application would not be required to use
>>> these PK's if they did not apply. All queries could be JPA queries.
>>> --Gordon
>>>
>>> -----Original Message-----
>>> From: Cheng.Fang_at_Sun.COM [mailto:Cheng.Fang_at_Sun.COM]On Behalf Of Cheng
>>> Fang
>>> Sent: Monday, July 31, 2006 3:30 PM
>>> To: dev_at_glassfish.dev.java.net
>>> Subject: primary tables with no primary key supported in EJB 3?
>>>
>>>
>>> Follow-up question for the user: is this supported in Glassfish EJB 3
>>> (Persistence)?
>>>
>>> http://gceclub.sun.com.cn/NASApp/sme/jive/thread.jsp?
>>> forum=22&thread=39131
>>>
>>> The reason he/she is asking this question is, his company used C and
>>> Informix 7 before, and it has been working pretty well for 7 years.
>>> They don't know why these tables have no primary key (most only have
>>> unique index), since original developers have left.
>>>
>>> Now they are working on a new project, and evaluating EJB 3
>>> (persistence) for possible use. They need to use these legacy
>>> data, but
>>> don't want change the database structure. They have hundreds of
>>> tables
>>> like this and some talbes contain several million records.
>>>
>>> In Glassfish EJB 3, is it possible to loosen the validation and allow
>>> these apps to deploy and run, maybe with some sort of warning? The
>>> user
>>> said situations like this is not uncommon. And any advice in general?
>>>
>>> Their app deploys and runs fine on Jboss.
>>>
>>> Thanks,
>>>
>>> Cheng
>>>
>>>
>>> Marina Vatkina wrote:
>>>
>>>
>>>> No, we do not support primary tables without primary keys for CMP
>>>> 2.1.
>>>>
>>>> regards,
>>>> -marina
>>>>
>>>> Cheng Fang wrote:
>>>>
>>>>
>>>>> This user is using ejb 2.1 on SJSAS PE 9. The Student table doesn't
>>>>> designate a primary key, but in ejb code he uses 'id' as if it was a
>>>>> primary key. The app failed to deploy on SJSAS 9. But he was able to
>>>>> deploy and run the same app on JBoss.
>>>>>
>>>>> error messages (hope you can tell something from a few keywords)
>>>>> Deploying application in domain failed; 运行 EJBC 时发生错 误 -- 来自
>>>>> EJB 编译器的致命错误 -- JDO74025: JDOCodeGenerator: 验 证应用程序
>>>>> “EJBModule1” 的模块“EJBModule1”中的 CMP Bean“Fhdsckfhz”时捕获异常:
>>>>> JDO72335: 如果与生 成的类 testsss.FhdsckfhzBean96247497_JDOState
>>>>> 对应
>>>>> 的 Bean 的表 fhdsckfhz 被映射为主表, 则它必须有主 键。请选择其它主
>>>>> 表或
>>>>> 验证模式文件的内容是否正确。
>>>>>
>>>>> Once he specified 'id' as primary key in database table, it deploys
>>>>> and runs fine. So the question is, does SJSAS 9 ejb 2.x support
>>>>> tables with no primary key?
>>>>>
>>>>> More details are here:
>>>>> http://gceclub.sun.com.cn/NASApp/sme/jive/thread.jsp?
>>>>> forum=22&thread=39131
>>>>>
>>>>>
>>>>>
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>
> Craig Russell
> clr@apache.org http://db.apache.org/jdo
>
>