Re: [gnome-db] append row to data model.

[Bas Driessen <bas driessen xobas com>]

On Thu, 2006-01-26 at 11:32 +0100, Vivien Malerba wrote:
> 2006/1/26, Bas Driessen <bas driessen xobas com>:
> >  On Thu, 2006-01-26 at 11:12 +0100, Vivien Malerba wrote:
> >  2006/1/26, Bas Driessen <bas driessen xobas com>:
> > > On Thu, 2006-01-26 at 10:49 +0100, Vivien Malerba wrote:
> > > 2006/1/26, Bas Driessen <bas driessen xobas com>:
> > > [...]
> > > >
> > > > I agree with the concept to address this issue, but I don't believe this
> > > > code above will work OK. If I append a row with values to the datamodel,
> > > it
> > > > returns the line number of the new row and it exits. At that point I
> > also
> > > > want to append it to the database. In the code above, you try to add the
> > > row
> > > > to the database if appending to the datamodel fails, but that is the
> > other
> > > > way around if I read it correctly. I will do a some testing.
> > >
> > > Calling the gda_data_model_row_append_values() will
> > > (because the
> > > GdaPostgresRecordset object does not implement the GdaDataModelRow's
> > > append_value() virtual function):
> > > * create a new GdaRow object initialized with the correct values
> > > * call the GdaDataModelRow's append_row() virtual function which is
> > > defined in gda-postgres-recordset.c:208, and will do the job.
> > > * return the row number of the new row.
> > >
> > > Tell me if it works
> > >
> > >
> > > If I change the gda_data_model_row_append_values as
> > below,
> > > it works OK. I just tested it.
> > >
> > > static gint
> > > gda_data_model_row_append_values (GdaDataModel *model,
> > > const GList *values, GError **error)
> > > {
> > > GdaRow *row;
> > >
> > > g_return_val_if_fail (GDA_IS_DATA_MODEL_ROW (model), -1);
> > > g_return_val_if_fail (CLASS (model)->append_values != NULL, -1);
> > >
> > > row = CLASS (model)->append_values (GDA_DATA_MODEL_ROW (model),
> > > values, error);
> > > if (row)
> > > {
> > > CLASS (model)->append_row (GDA_DATA_MODEL_ROW (model), row,
> > > error);
> > > return gda_row_get_number (row);
> > > }
> > > else
> > > return -1;
> > > }
> > >
> > >
> >
> > Right, but this results in the GdaRow being added twice to the data
> > Hash data model (once when calling "row = CLASS
> > (model)->append_values...", and once when calling "CLASS
> > (model)->append_row").
> >
> > May I suggest that you:
> > 1) modify the above function to
> > static gint
> > gda_data_model_row_append_values (GdaDataModel *model,
> > const GList
> > *values, GError **error)
> > {
> >  GdaRow *row;
> >
> >  g_return_val_if_fail (GDA_IS_DATA_MODEL_ROW (model), -1);
> >  g_return_val_if_fail (CLASS (model)->append_values != NULL, -1);
> >
> >  row = CLASS (model)->append_values (GDA_DATA_MODEL_ROW
> > (model), values, error);
> >  if (row)
> >  return gda_row_get_number (row);
> >  else
> >  return -1;
> > }
> >
> > 2) and modify line 206 of gda-data-model-hash.c to:
> > if (! GDA_DATA_MODEL_ROW_CLASS (G_OBJECT_GET_CLASS
> > (model))->append_row (model, row, error)) {
> >
> > The idea is to make the gda_data_model_hash_append_values()
> > function call
> > GdaPostgresRecordset's defined append_row() instead of calling
> > directly the GdaDataModelHash's append_row() function (which anyway
> > gets called at the end of the GdaPostgresRecordset's defined
> > append_row() function).
> >
> > Can you try that?
> >
> >
> >  Thanks Vivian, that works OK. 1 record added to the table in the database
> > and 1 row added to the datamodel. Perfect! Just a concern. This will now
> > only work for hash implementations. I believe that the MySQL provider uses
> > something else (have to look into again). Can we make this change more
> > generic?
> >
>
> Yes, you're right, the Mysql recordset inherits the GdaDataModelArray.
> Here is what I propose: correct the
> gda_data_model_array_append_values() to call the add_row() virtual
> function instead of the lines 137 to 139 which do that.
>
> I'll correct it in my local copy.
OK, understood Vivian. Will do some testing with MySQL in the morning. To avoid that we overlap any source roll-ins. I will NOT apply anything to CVS HEAD unless you advise me otherwise. Once you have applied your local copy to CVS HEAD, I will re-test and double check if all works OK.

Thanks for your help today!

Bas.