Re: [gnome-db] Proveedores GDA para Firebird y PostgreSQL

[Iago Rubio <iago iagorubio com>]

On Sat, 2005-07-16 at 14:55 +0200, Vivien Malerba wrote:
> On 7/15/05, Juan Manuel Mouriz <jmouriz gmail com> wrote:
> > Hola,
> > 
> > Quiero consultar las características que soporta un proveedor sin
> > tener que estar conectado. Para ello llamo al método "supports"
> > cargando previamente el módulo del proveedor. El problema es que casi
> > todos los proveedores me permiten pasar NULL el la conexión excepto el
> > Firebird:
> > 
> > /* supports handler for the GdaFirebirdProvider class */
> > static gboolean
> > gda_firebird_provider_supports (GdaServerProvider *provider,
> >                                 GdaConnection *cnc,
> >                                 GdaConnectionFeature feature)
> > {
> >         g_return_val_if_fail (GDA_IS_FIREBIRD_PROVIDER (provider), FALSE);
> > >>>  g_return_val_if_fail (GDA_IS_CONNECTION (cnc), FALSE);
> > 
> >         switch (feature) {
> >                 case GDA_CONNECTION_FEATURE_VIEWS:
> >                 case GDA_CONNECTION_FEATURE_SQL:
> >                 case GDA_CONNECTION_FEATURE_TRANSACTIONS:
> >                 case GDA_CONNECTION_FEATURE_AGGREGATES:
> >                         return TRUE;
> >                 case GDA_CONNECTION_FEATURE_TRIGGERS:
> >                 case GDA_CONNECTION_FEATURE_INDEXES:
> >                 case GDA_CONNECTION_FEATURE_PROCEDURES:
> >                 case GDA_CONNECTION_FEATURE_USERS:
> >                 case GDA_CONNECTION_FEATURE_BLOBS:
> >                 default:
> >                         break;
> >         }
> > 
> >         return FALSE;
> > }
> 
> That is corrected in CVS!
> 
> > 
> > ¿Existe la posibilidad que esta línea desaparezca en futuras
> > versiones?, pues realmente "cnc" no se usa aquí. Y en general este
> > método se accede mediante el API de GDA que ya hace esta comprobación
> > (gda_connections_supports).

[Translated]

"May be possible to drop this line in future versions ? as "cnc" is not
really used here. Usually this method is accessed through GDA's API,
where this check is also done (gda_connections_supports)."

> > Otro problema que veo es que el proveedor de PostgreSQL NO hace esta
> > verificación:

"Another problem I see is PostgreeSQL provider NOT making this
verification."
 
> > static gboolean gda_postgres_provider_supports (GdaServerProvider *provider,
> >                                                 GdaConnection *cnc,
> >                                                 GdaConnectionFeature feature)
> > {
> >         GdaPostgresProvider *pgprv = (GdaPostgresProvider *) provider;
> >         GdaPostgresConnectionData *priv_data;
> > 
> >         g_return_val_if_fail (GDA_IS_POSTGRES_PROVIDER (pgprv), FALSE);
> > 
> >         switch (feature) {
> >         case GDA_CONNECTION_FEATURE_AGGREGATES :
> >         case GDA_CONNECTION_FEATURE_INDEXES :
> >         case GDA_CONNECTION_FEATURE_INHERITANCE :
> >         case GDA_CONNECTION_FEATURE_PROCEDURES :
> >         case GDA_CONNECTION_FEATURE_SEQUENCES :
> >         case GDA_CONNECTION_FEATURE_SQL :
> >         case GDA_CONNECTION_FEATURE_TRANSACTIONS :
> >         case GDA_CONNECTION_FEATURE_TRIGGERS :
> >         case GDA_CONNECTION_FEATURE_USERS :
> >         case GDA_CONNECTION_FEATURE_VIEWS :
> >         case GDA_CONNECTION_FEATURE_BLOBS :
> >                 return TRUE;
> >         case GDA_CONNECTION_FEATURE_NAMESPACES :
> >                 priv_data = g_object_get_data (G_OBJECT (cnc),
> > OBJECT_DATA_POSTGRES_HANDLE);
> >                 if (priv_data->version_float >= 7.3)
> >                         return TRUE;
> >         default :
> >                 break;
> >         }
> > 
> >         return FALSE;
> > }
> >
> > Sin embargo la usa para consultar la característica
> > GDA_CONNECTION_FEATURE_NAMESPACES. 

"But it uses it to request the setting
GDA_CONNECTION_FEATURE_NAMESPACES."

> La pregunta es: ¿Existe la
> > posibilidad que si en algún momento se agregue este comprobación se
> > haga sólo justo antes de usarla?, es decir justo antes de la línea
> > "priv_data = g_object_get_data (G_OBJECT (cnc)".

[Ouch! that's not easy at all, it's freely translated]

"The question here is:  If you'll add this check in a near future, Could
be possible to add it just before to use it ? I mean just before the
line:
'priv_data = g_object_get_data (G_OBJECT (cnc)'."
 
> > Por último. Luego de cargar el módulo, llamo al método
> > "plugin_create_provider" para crear una instancia del proveedor y
> > poder consultalo. El problema es que luego de hacer esto quiero
> > descargar el módulo con g_modulo_unload pero el tipo GLib
> > "GdaXXXProvider" queda registrado, hay alguna forma de
> > "desregistrarlo"?.

"And finally: after to load the module, I call the
'plugin_create_provider' method, to create a provider's instance to be
able to make requests to it. Before to do it, I unload the module with
'g_module_unload' but GLib's type 'GdaXXXProvider' is still registered.
Is there any way to unregister it ? "

> > 
> > Gracias
> 
> Sorry, but I don't understand Spanish enough; can you try to post in English ?

I hope this cheap translation helps :)
-- 
Iago Rubio