Well the confusion IMO as a user is that I specifically asked for only
creation scripts to be generated, but got both creation and drop
scripts. Thats not going to change by making schema-generation-target
required. Even this is still confusing:
javax.persistence.schema-generation-action=create
javax.persistence.schema-generation-target=scripts
javax.persistence.ddl-create-script-target=<something>
javax.persistence.ddl-drop-script-target=<something>
because i would not expect to get a drop script. But if I read the
other parts of the spec correctly, the following actually results in an
exception:
javax.persistence.schema-generation-action=create
javax.persistence.schema-generation-target=scripts
javax.persistence.ddl-create-script-target=<something>
The exception is because 'javax.persistence.ddl-drop-script-target' is
not specified, again even though i just said I only want create scripts
generated.
On Thu 31 Jan 2013 02:13:20 PM CST, Linda DeMichiel wrote:
>
>
> On 1/31/2013 11:52 AM, Steve Ebersole wrote:
>> I also am not sure about this passage in discussing
>> 'javax.persistence.ddl-create-script-target' and
>> 'javax.persistence.ddl-drop-script-target':
>>
>> <quote>
>> The persistence provider must produce both create and drop scripts if
>> the corresponding
>> DDL targets are specified. This is independent of whether a drop
>> action is included in the
>> value passed for the javax.persistence.schema-generation-action
>> property.
>> </quote>
>>
>> To me, this sounds like you are saying that the following config will
>> generate both create and drop scripts:
>>
>> javax.persistence.schema-generation-action=create
>> javax.persistence.ddl-create-script-target=<something>
>> javax.persistence.ddl-drop-script-target=<something>
>>
>> even though the config explicitly specified just create scripts. Is
>> that your intent?
>>
>
> yes
>
>> Same for:
>>
>> javax.persistence.schema-generation-action=drop
>> javax.persistence.ddl-create-script-target=<something>
>> javax.persistence.ddl-drop-script-target=<something>
>>
>> that is supposed to generate both create and drop scripts?
>>
>
> yes
>
>>
>> Perhaps the reasoning is that
>> javax.persistence.schema-generation-action is really just geared towards
>> javax.persistence.schema-generation-action=database.
>
> partially. also it was intended to control whether any action would
> be taken.
>
> I'm thinking that all this might be clearer if we required
> schema-generation-target to be specified.
>
> But if that is the case, maybe we ought to rename the setting to be
>> more explicit of that fact or at least document it in the discussion
>> of 'javax.persistence.schema-generation-action'
>>
>>
>> On 01/31/2013 01:13 PM, Steve Ebersole wrote:
>>> One quick question.
>>>
>>> For 'javax.persistence.schema-generation-source' values of
>>> metadata-then-scripts and scripts-then-metadata is the
>>> order the same for both create and drop?
>>>
>>> I can envision a situation, for example, with metadata-then-scripts
>>> where the metadata creates a table and then the
>>> script creates a procedure. I am not sure that all databases will
>>> allow you to drop the table if other database
>>> objects refer to it. Would it be better to say that the defined
>>> order (x-then-y) applies to create, but the reverse
>>> order (y-then-x) applies to drop?
>>>
>>>
>>> On 01/31/2013 12:49 PM, Steve Ebersole wrote:
>>>> These look great. Thanks Linda.
>>>>
>>>> On 01/28/2013 05:14 PM, Linda DeMichiel wrote:
>>>>> There are currently a few open issues in schema generation that need
>>>>> clarification. These pertain to sections 9.4 ("Schema generation")
>>>>> and 8.2.1.9 ("properties") in the spec.
>>>>>
>>>>> I've made some clarifications and proposed some additions to the
>>>>> metadata for schema generation as described below. The draft I've
>>>>> just uploaded reflects these changes
>>>>> (http://java.net/projects/jpa-spec/downloads/download/JavaPersistence01282013.pdf).
>>>>>
>>>>> Please review these sections and post any feedback. Changes are
>>>>> summarized below.
>>>>>
>>>>> ----
>>>>>
>>>>> Section 9.4
>>>>>
>>>>> This section isn't sufficiently clear about requirements for the
>>>>> specification of schema-generation-action and
>>>>> schema-generation-target.
>>>>>
>>>>> I've clarified that schema-generation-action must be specified or no
>>>>> actions will be taken. This was an assumed default in the current
>>>>> public draft, but IMO not sufficiently explicit.
>>>>>
>>>>> Given the clarification to schema-generation-action, I think it now
>>>>> makes sense for schema-generation-target to have default values.
>>>>> That is, if script targets are specified by the properties for
>>>>> scripts,
>>>>> then generation actions should default into scripts. If not, actions
>>>>> should be directly into the database.
>>>>>
>>>>> The current public draft assumes that if script sources are
>>>>> specified,
>>>>> generation should occur from scripts exclusively; and conversely, if
>>>>> script sources are not specified, generation should occur exclusively
>>>>> from the ORM metadata. I've gotten feedback that this wasn't
>>>>> sufficiently
>>>>> flexible, and that we should support a combination of ORM and script
>>>>> sources. (For example, consider the case where generation should
>>>>> occur
>>>>> from scripts, but it is desirable to add stored procedures to the
>>>>> database.)
>>>>> I therefore propose that we add a schema-generation-source property
>>>>> that will support such combination. Again, if script sources are
>>>>> specified
>>>>> by the properties for scripts, then generation will default to use of
>>>>> only script sources; if script sources aren't specified, then
>>>>> generation
>>>>> will default from the ORM metadata.
>>>>>
>>>>> I've also received feedback (from our JPA/EE integration engineer)
>>>>> that
>>>>> we need to specify that in Java EE environments that strings
>>>>> corresponding
>>>>> to file URLs must use absolute (and not relative) paths. I've
>>>>> added that
>>>>> clarification as well.
>>>>>
>>>>>
>>>>> Section 8.2.1.9
>>>>>
>>>>> In the current public draft, this section lacks information as to how
>>>>> script locations are specified. I've added a clarification that
>>>>> scripts packaged as part of the application must be specified
>>>>> relative
>>>>> to the root of the persistence unit, as we do for other packaged
>>>>> artifacts. I've also added a clarification about the expectations for
>>>>> use of file URLs in Java EE environments as above.
>>>>>
>>>>> Finally, when I wrote this up initially, I was reluctant to add
>>>>> metadata for schema generation actions (including targets) because I
>>>>> believed that such metadata should not be specific to the persistence
>>>>> unit definition itself. It seems however that people expect that the
>>>>> use of these properties (as specified in section 9.4) will be
>>>>> available anyway, whether they are specified in the spec document or
>>>>> not, and that some vendors will support these anyway as well.
>>>>> Further, this additional metadata may facilitate ease of use in
>>>>> prototyping/development environments. I've therefore added these
>>>>> properties into 8.2.1.9. If you disagree, please speak up.
>>>>>
>>>>>
>>>>> thanks,
>>>>>
>>>>> -Linda
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>
>>