Home » Modeling » EMF » XSD ID -> EMF ID -> hibernate id
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| Re: XSD ID -> EMF ID -> hibernate id [message #423613 is a reply to message #423612] |
Fri, 03 October 2008 00:10   |
Eclipse User |
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Originally posted by: cdamus.zeligsoft.com
Hi, Andrew,
EMF's EObject IDs are intended to be resource-unique, as in XSD. The
UUID utility is a convenience for generating IDs that probably are
universally unique, but nothing in EMF expects this property.
HTH,
Christian
Andrew H wrote:
> As discussed in
> http://www.eclipse.org/newsportal/article.php?id=36086&g roup=eclipse.tools.emf#36086
>
>
> I started with some XSD's, generated EMF models and then persisted with
> Teneo. Fields that were declared in XSD as ID fields went into EMF as ID
> fields and then as id elements in the hibernate mappings. i.e. these
> fields became primary key fields.
>
> However, the XSD authors never intended them to be globally unique, just
> unique within a single document. They use IDREF fields elsewhere in the
> doc to refer to them.
>
> Consequently they are not suitable as id fields in the hibernate mappings.
>
> I fixed this with Martin's help by turning off the mapping from EMF ID
> to hibernate id.
>
> However, its not clear to me whether this was the best place to fix it.
> Is the semantics of ID in EMF that the field is intended to be a unique
> primary key for that class?
>
> If so then I should probably sever the mapping of XSD ID to EMF ID for
> these fields instead? If so how do I do that?
>
> Thoughts?
>
>
>
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| Re: XSD ID -> EMF ID -> hibernate id [message #423648 is a reply to message #423613] |
Sat, 04 October 2008 01:08 |
 Andrew H
Messages: 117
Registered: July 2009 |
Senior Member |
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Thanks Christian
So I guess it comes down to what a resource is. In some cases it might
be a document, in others a table in a DB.
Christian W. Damus wrote:
> Hi, Andrew,
>
> EMF's EObject IDs are intended to be resource-unique, as in XSD. The
> UUID utility is a convenience for generating IDs that probably are
> universally unique, but nothing in EMF expects this property.
>
> HTH,
>
> Christian
>
> Andrew H wrote:
>> As discussed in
>> http://www.eclipse.org/newsportal/article.php?id=36086&g roup=eclipse.tools.emf#36086
>>
>>
>> I started with some XSD's, generated EMF models and then persisted
>> with Teneo. Fields that were declared in XSD as ID fields went into
>> EMF as ID fields and then as id elements in the hibernate mappings.
>> i.e. these fields became primary key fields.
>>
>> However, the XSD authors never intended them to be globally unique,
>> just unique within a single document. They use IDREF fields elsewhere
>> in the doc to refer to them.
>>
>> Consequently they are not suitable as id fields in the hibernate
>> mappings.
>>
>> I fixed this with Martin's help by turning off the mapping from EMF ID
>> to hibernate id.
>>
>> However, its not clear to me whether this was the best place to fix
>> it. Is the semantics of ID in EMF that the field is intended to be a
>> unique primary key for that class?
>>
>> If so then I should probably sever the mapping of XSD ID to EMF ID for
>> these fields instead? If so how do I do that?
>>
>> Thoughts?
>>
>>
>>
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| Re: XSD ID -> EMF ID -> hibernate id [message #423650 is a reply to message #423648] |
Sat, 04 October 2008 09:34 |
Martin Taal
Messages: 5468
Registered: July 2009 |
Senior Member |
|
|
Hi Andres,
Or the resource represents the whole database, with Teneo a resource is connected to the database as
a whole, i.e. a Teneo EMF resource uses a hibernate session and with queries you can load data from
all the tables into the resource.
gr. Martin
andrew987650000@yahoo.com.au wrote:
> Thanks Christian
>
> So I guess it comes down to what a resource is. In some cases it might
> be a document, in others a table in a DB.
>
> Christian W. Damus wrote:
>> Hi, Andrew,
>>
>> EMF's EObject IDs are intended to be resource-unique, as in XSD. The
>> UUID utility is a convenience for generating IDs that probably are
>> universally unique, but nothing in EMF expects this property.
>>
>> HTH,
>>
>> Christian
>>
>> Andrew H wrote:
>>> As discussed in
>>> http://www.eclipse.org/newsportal/article.php?id=36086&g roup=eclipse.tools.emf#36086
>>>
>>>
>>> I started with some XSD's, generated EMF models and then persisted
>>> with Teneo. Fields that were declared in XSD as ID fields went into
>>> EMF as ID fields and then as id elements in the hibernate mappings.
>>> i.e. these fields became primary key fields.
>>>
>>> However, the XSD authors never intended them to be globally unique,
>>> just unique within a single document. They use IDREF fields elsewhere
>>> in the doc to refer to them.
>>>
>>> Consequently they are not suitable as id fields in the hibernate
>>> mappings.
>>>
>>> I fixed this with Martin's help by turning off the mapping from EMF
>>> ID to hibernate id.
>>>
>>> However, its not clear to me whether this was the best place to fix
>>> it. Is the semantics of ID in EMF that the field is intended to be a
>>> unique primary key for that class?
>>>
>>> If so then I should probably sever the mapping of XSD ID to EMF ID
>>> for these fields instead? If so how do I do that?
>>>
>>> Thoughts?
>>>
>>>
>>>
--
With Regards, Martin Taal
Springsite/Elver.org
Office: Hardwareweg 4, 3821 BV Amersfoort
Postal: Nassaulaan 7, 3941 EC Doorn
The Netherlands
Cell: +31 (0)6 288 48 943
Tel: +31 (0)84 420 2397
Fax: +31 (0)84 225 9307
Mail: mtaal@springsite.com - mtaal@elver.org
Web: www.springsite.com - www.elver.org
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| Re: XSD ID -> EMF ID -> hibernate id [message #423651 is a reply to message #423650] |
Sat, 04 October 2008 09:36 |
Martin Taal
Messages: 5468
Registered: July 2009 |
Senior Member |
|
|
And here with the correct spelling of your name, sorry (the s and w are too close to eachother for
my fingers apparently :-)
Hi Andrew,
Or the resource represents the whole database, with Teneo a resource is
connected to the database as a whole, i.e. a Teneo EMF resource uses a
hibernate session and with queries you can load data from all the tables
into the resource.
gr. Martin
Martin Taal wrote:
>
> andrew987650000@yahoo.com.au wrote:
>> Thanks Christian
>>
>> So I guess it comes down to what a resource is. In some cases it might
>> be a document, in others a table in a DB.
>>
>> Christian W. Damus wrote:
>>> Hi, Andrew,
>>>
>>> EMF's EObject IDs are intended to be resource-unique, as in XSD. The
>>> UUID utility is a convenience for generating IDs that probably are
>>> universally unique, but nothing in EMF expects this property.
>>>
>>> HTH,
>>>
>>> Christian
>>>
>>> Andrew H wrote:
>>>> As discussed in
>>>> http://www.eclipse.org/newsportal/article.php?id=36086&g roup=eclipse.tools.emf#36086
>>>>
>>>>
>>>> I started with some XSD's, generated EMF models and then persisted
>>>> with Teneo. Fields that were declared in XSD as ID fields went into
>>>> EMF as ID fields and then as id elements in the hibernate mappings.
>>>> i.e. these fields became primary key fields.
>>>>
>>>> However, the XSD authors never intended them to be globally unique,
>>>> just unique within a single document. They use IDREF fields
>>>> elsewhere in the doc to refer to them.
>>>>
>>>> Consequently they are not suitable as id fields in the hibernate
>>>> mappings.
>>>>
>>>> I fixed this with Martin's help by turning off the mapping from EMF
>>>> ID to hibernate id.
>>>>
>>>> However, its not clear to me whether this was the best place to fix
>>>> it. Is the semantics of ID in EMF that the field is intended to be a
>>>> unique primary key for that class?
>>>>
>>>> If so then I should probably sever the mapping of XSD ID to EMF ID
>>>> for these fields instead? If so how do I do that?
>>>>
>>>> Thoughts?
>>>>
>>>>
>>>>
>
>
--
With Regards, Martin Taal
Springsite/Elver.org
Office: Hardwareweg 4, 3821 BV Amersfoort
Postal: Nassaulaan 7, 3941 EC Doorn
The Netherlands
Cell: +31 (0)6 288 48 943
Tel: +31 (0)84 420 2397
Fax: +31 (0)84 225 9307
Mail: mtaal@springsite.com - mtaal@elver.org
Web: www.springsite.com - www.elver.org
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| Re: XSD ID -> EMF ID -> hibernate id [message #423654 is a reply to message #423651] |
Sat, 04 October 2008 16:49 |
| Eclipse User |
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Originally posted by: cdamus.zeligsoft.com
Hi, Martin,
Perhaps Andrew would enjoy being Spanish for a day?
You should use the Dvorak layout, as I do. There is a greater
separation between the S and the W. My own problem is between the N and
S, and the A and O. I sometimes sign my own name as Christios ... looks
vaguely Greek.
:-D
On a more serious note, I think the mapping of EMF's resource do the
database as a whole is very intuitive. It's convenient to have a closed
universe containing everything, and external references modeled simply
as URIs, which makes for a very explicit proxy concept.
cW
Martin Taal wrote:
> And here with the correct spelling of your name, sorry (the s and w are
> too close to eachother for my fingers apparently :-)
>
> Hi Andrew,
> Or the resource represents the whole database, with Teneo a resource is
> connected to the database as a whole, i.e. a Teneo EMF resource uses a
> hibernate session and with queries you can load data from all the tables
> into the resource.
>
> gr. Martin
>
> Martin Taal wrote:
>>
>> andrew987650000@yahoo.com.au wrote:
>>> Thanks Christian
>>>
>>> So I guess it comes down to what a resource is. In some cases it
>>> might be a document, in others a table in a DB.
>>>
>>> Christian W. Damus wrote:
>>>> Hi, Andrew,
>>>>
>>>> EMF's EObject IDs are intended to be resource-unique, as in XSD.
>>>> The UUID utility is a convenience for generating IDs that probably
>>>> are universally unique, but nothing in EMF expects this property.
>>>>
>>>> HTH,
>>>>
>>>> Christian
>>>>
>>>> Andrew H wrote:
>>>>> As discussed in
>>>>> http://www.eclipse.org/newsportal/article.php?id=36086&g roup=eclipse.tools.emf#36086
>>>>>
>>>>>
>>>>> I started with some XSD's, generated EMF models and then persisted
>>>>> with Teneo. Fields that were declared in XSD as ID fields went into
>>>>> EMF as ID fields and then as id elements in the hibernate mappings.
>>>>> i.e. these fields became primary key fields.
>>>>>
>>>>> However, the XSD authors never intended them to be globally unique,
>>>>> just unique within a single document. They use IDREF fields
>>>>> elsewhere in the doc to refer to them.
>>>>>
>>>>> Consequently they are not suitable as id fields in the hibernate
>>>>> mappings.
>>>>>
>>>>> I fixed this with Martin's help by turning off the mapping from EMF
>>>>> ID to hibernate id.
>>>>>
>>>>> However, its not clear to me whether this was the best place to fix
>>>>> it. Is the semantics of ID in EMF that the field is intended to be
>>>>> a unique primary key for that class?
>>>>>
>>>>> If so then I should probably sever the mapping of XSD ID to EMF ID
>>>>> for these fields instead? If so how do I do that?
>>>>>
>>>>> Thoughts?
>>>>>
>>>>>
>>>>>
>>
>>
>
>
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| Re: XSD ID -> EMF ID -> hibernate id [message #423759 is a reply to message #423654] |
Tue, 07 October 2008 06:16 |
Andrew H
Messages: 117
Registered: July 2009 |
Senior Member |
|
|
Thanks Christios & Marten :-)
So I think the problem then in this case is the association with XSD ID
and EMF ID. The XSD's that I originally imported are for B2B applications.
They use XML ID for references within a document. I should stop these
mapping to EMF ID fields as this implies uniqueness withing our database
for these objects.
thanks for everyones thoughts
Christian W. Damus wrote:
> Hi, Martin,
> Perhaps Andrew would enjoy being Spanish for a day?
> You should use the Dvorak layout, as I do. There is a greater
> separation between the S and the W. My own problem is between the N and
> S, and the A and O. I sometimes sign my own name as Christios ... looks
> vaguely Greek.
> :-D
> On a more serious note, I think the mapping of EMF's resource do the
> database as a whole is very intuitive. It's convenient to have a closed
> universe containing everything, and external references modeled simply
> as URIs, which makes for a very explicit proxy concept.
> cW
> Martin Taal wrote:
>> And here with the correct spelling of your name, sorry (the s and w are
>> too close to eachother for my fingers apparently :-)
>>
>> Hi Andrew,
>> Or the resource represents the whole database, with Teneo a resource is
>> connected to the database as a whole, i.e. a Teneo EMF resource uses a
>> hibernate session and with queries you can load data from all the tables
>> into the resource.
>>
>> gr. Martin
>>
>> Martin Taal wrote:
>>>
>>> andrew987650000@yahoo.com.au wrote:
>>>> Thanks Christian
>>>>
>>>> So I guess it comes down to what a resource is. In some cases it
>>>> might be a document, in others a table in a DB.
>>>>
>>>> Christian W. Damus wrote:
>>>>> Hi, Andrew,
>>>>>
>>>>> EMF's EObject IDs are intended to be resource-unique, as in XSD.
>>>>> The UUID utility is a convenience for generating IDs that probably
>>>>> are universally unique, but nothing in EMF expects this property.
>>>>>
>>>>> HTH,
>>>>>
>>>>> Christian
>>>>>
>>>>> Andrew H wrote:
>>>>>> As discussed in
>>>>>>
http://www.eclipse.org/newsportal/article.php?id=36086&g roup=eclipse.tools.emf#36086
>>>>>>
>>>>>>
>>>>>> I started with some XSD's, generated EMF models and then persisted
>>>>>> with Teneo. Fields that were declared in XSD as ID fields went into
>>>>>> EMF as ID fields and then as id elements in the hibernate mappings.
>>>>>> i.e. these fields became primary key fields.
>>>>>>
>>>>>> However, the XSD authors never intended them to be globally unique,
>>>>>> just unique within a single document. They use IDREF fields
>>>>>> elsewhere in the doc to refer to them.
>>>>>>
>>>>>> Consequently they are not suitable as id fields in the hibernate
>>>>>> mappings.
>>>>>>
>>>>>> I fixed this with Martin's help by turning off the mapping from EMF
>>>>>> ID to hibernate id.
>>>>>>
>>>>>> However, its not clear to me whether this was the best place to fix
>>>>>> it. Is the semantics of ID in EMF that the field is intended to be
>>>>>> a unique primary key for that class?
>>>>>>
>>>>>> If so then I should probably sever the mapping of XSD ID to EMF ID
>>>>>> for these fields instead? If so how do I do that?
>>>>>>
>>>>>> Thoughts?
>>>>>>
>>>>>>
>>>>>>
>>>
>>>
>>
>>
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