[fdo-internals] FDO RFC 7 - Add NewMethodstoFdoClassDefinition-Take II

[Haris Kurtagic]

As far as I understand this conversation:

IsVirtual attribute will be set for FDO Classes which are based on
database View so it will mark that FDO class is not updatable.
View can be updatable or not, you cannot determine if the view is
updatable or not.

Even FDO provider can't determine if View is updatable the provider
should set attribute that FDO Class is virtual which will mean that it
is not updatable FDO Class.

I think this is not the way to go.

Haris

-----Original Message-----
From: fdo-internals-bounces at lists.osgeo.org
[mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Barbara
Zoladek
Sent: Tuesday, July 31, 2007 3:59 AM
To: FDO Internals Mail List
Subject: RE: [fdo-internals] FDO RFC 7 - Add
NewMethodstoFdoClassDefinition-Take II

> I am trying to understand how FDO client application can use
information
> that FDO Class is based on RDBMS View ?

Since the view updateability cannot be determined reliably, the
application knowing that the class is based on the virtual object would
be able to prevent data editing. The alternative would be to let the
user insert/update data and hit the error at the target datastore and
tell user that the operation is invalid. That's not the right approach.
Another example could be the case when application is caching data and
must keep caches is sync. 

> For RDBMS application View can be same as Table. Data can be
modifided,
> index created, triggers created, etc..
> For application's there is no difference if data is coming from View
or
> Table.

Well, not exactly. Only simple views are updateable. Views based on
complex queries require instead-of-triggers to make them updateable. You
cannot determine if the view is updateable or not. True that for
example, SQL Server allows creating an index (Oracle does not), but
still it depends on the underlying database object. 

Thanks,
Barbara.

> -----Original Message-----
> From: fdo-internals-bounces at lists.osgeo.org [mailto:fdo-internals-
> bounces at lists.osgeo.org] On Behalf Of Haris Kurtagic
> Sent: Monday, July 30, 2007 5:05 PM
> To: FDO Internals Mail List
> Subject: RE: [fdo-internals] FDO RFC 7 - Add New
MethodstoFdoClassDefinition-Take II
> 
> I am trying to understand how FDO client application can use
information
> that FDO Class is based on RDBMS View ?
> 
> For RDBMS application View can be same as Table. Data can be
modifided,
> index created, triggers created, etc..
> For application's there is no difference if data is coming from View
or
> Table.
> 
> Haris
> 
> -----Original Message-----
> From: fdo-internals-bounces at lists.osgeo.org
> [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Barbara
> Zoladek
> Sent: Monday, July 30, 2007 10:50 PM
> To: FDO Internals Mail List
> Subject: RE: [fdo-internals] FDO RFC 7 - Add New Methods
> toFdoClassDefinition-Take II
> 
> Hi Haris,
> 
> Yes, that's the case.
> 
> Thanks,
> Barbara.
> 
> > -----Original Message-----
> > From: fdo-internals-bounces at lists.osgeo.org [mailto:fdo-internals-
> > bounces at lists.osgeo.org] On Behalf Of Haris Kurtagic
> > Sent: Monday, July 30, 2007 4:43 PM
> > To: FDO Internals Mail List
> > Subject: RE: [fdo-internals] FDO RFC 7 - Add New Methods to
> FdoClassDefinition-Take
> > II
> >
> > Hi Barbara,
> >
> > I don't understand in which cases provider should set that FDO Class
> is
> > Virtual.
> >
> > In the case when FDO Class is based on RDBMS View ?
> >
> > Haris
> >
> > -----Original Message-----
> > From: fdo-internals-bounces at lists.osgeo.org
> > [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Barbara
> > Zoladek
> > Sent: Monday, July 30, 2007 9:35 PM
> > To: FDO Internals Mail List
> > Subject: [fdo-internals] FDO RFC 7 - Add New Methods to
> > FdoClassDefinition -Take II
> >
> > Hi,
> >
> > Thanks for all your comments on RFC-7.
> > The new version is now available:
> >
> >  http://trac.osgeo.org/fdo/wiki/FDORfc7
> >
> > Thanks,
> > Barbara.
> >
> > _______________________________________________
> > fdo-internals mailing list
> > fdo-internals at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/fdo-internals
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> > http://lists.osgeo.org/mailman/listinfo/fdo-internals
> 
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