[Mono-list] DbDataAdapter.Fill patch

[Alan Tam]

May I know where is it stated that one DataAdapter updates only one table? I
also believe so, but I found the code very strange, including trying to find
the DataTable associated to each schemaRow. I'm totally confused.

Regards,
Alan

----- Original Message -----
From: "Aleksey Demakov" <avd@openlinksw.com>
To: "Alan Tam" <Tam@SiuLung.com>
Cc: <mono-list@ximian.com>
Sent: Tuesday, February 25, 2003 5:24 PM
Subject: Re: [Mono-list] DbDataAdapter.Fill patch


> So what's wrong with it? I think that a DataAdapter at one time
> should update only one table. It's absolutely wrong to iterate
> through all the tables in the DataSet because the DataAdapter
> contains only one set of update commands while different tables
> require different commands.
>
> Regards,
> Aleksey
>
> Alan Tam wrote:
> > The bottom half of the patch has been applied. Thank you.
> >
> > For the upper half, we may need more discussion. As far as I've observed,
the
> > patch changes the code to simulate Microsoft behavior, which seems to be a
> > wrong behavior. I wonder if we should follow suit.
> >
> > Regards,
> > Alan
> >
> > ----- Original Message -----
> > From: "Aleksey Demakov" <avd@openlinksw.com>
> > To: <mono-list@ximian.com>
> > Sent: Wednesday, January 22, 2003 4:37 AM
> > Subject: [Mono-list] DbDataAdapter.Fill patch
> >
> >
> >
> >>Hi all,
> >>
> >>I've found that the DbDataAdapter.Update (DataTable dataTable)
> >>and Update (DataSet dataSet, string sourceTable) methods
> >>iterate through all tables of the given dataSet and try
> >>to update them with this DataAdapter. I believe that
> >>this is incorrect.
> >>
> >>The dataSet can contain multiple DataTables which are
> >>Filled using different DataAdapters with different
> >>select/insert/delete/update commans. Consequently
> >>one DataAdapter cannot be be able to perform all the
> >>needed updates.
> >>
> >>Unfortunately, the .NET docs are silent about this
> >>issue. But I believe that DbDataAdapter.Update methods
> >>should be symmetric to Fill methods. So as Fill (DataSet)
> >>method fills only one DataSet table with default
> >>name "Table", the Update (DataSet) method should
> >>only update default table. And Update (DataSet, string)
> >>method should only update the specified table.
> >>
> >>The attached patch fixes also another problem.
> >>The original code might pass a null DataTableMapping
> >>value which is then used to create a RowUpdatingEventArgs
> >>instance. So RowUpdatingEvent handler (for instance
> >>CommandBuilder) could get null DataTableMapping which
> >>might be unexpected. The patch makes sure that a non-null
> >>DataTableMapping is passed.
> >>
> >>Regards,
> >>Aleksey
> >>
> >
> >
> >
>
> -----------------------------------------------------------------------------
--
> > -
> >
> >
> >
> >>Index: DbDataAdapter.cs
> >>===================================================================
> >>RCS file: /mono/mcs/class/System.Data/System.Data.Common/DbDataAdapter.cs,v
> >>retrieving revision 1.21
> >>diff -u -r1.21 DbDataAdapter.cs
> >>--- DbDataAdapter.cs 12 Nov 2002 13:47:37 -0000 1.21
> >>+++ DbDataAdapter.cs 21 Jan 2003 10:05:50 -0000
> >>@@ -356,10 +356,7 @@
> >>
> >>  public override int Update (DataSet dataSet)
> >>  {
> >>- int result = 0;
> >>- foreach (DataTable table in dataSet.Tables)
> >>- result += Update (table);
> >>- return result;
> >>+ return Update (dataSet, "Table");
> >>  }
> >>
> >>  public int Update (DataTable dataTable)
> >>@@ -447,11 +444,16 @@
> >>
> >>  public int Update (DataSet dataSet, string sourceTable)
> >>  {
> >>- int result = 0;
> >>- DataTableMapping tableMapping = TableMappings [sourceTable];
> >>- foreach (DataTable dataTable in dataSet.Tables)
> >>- result += Update (dataTable, tableMapping);
> >>- return result;
> >>+ MissingMappingAction mappingAction = MissingMappingAction;
> >>+ if (mappingAction == MissingMappingAction.Ignore)
> >>+ mappingAction = MissingMappingAction.Error;
> >>+ DataTableMapping tableMapping =
> >
> > DataTableMappingCollection.GetTableMappingBySchemaAction (TableMappings,
> > sourceTable, sourceTable, mappingAction);
> >
> >>+
> >>+ DataTable dataTable = dataSet.Tables[tableMapping.DataSetTable];
> >>+ if (dataTable == null)
> >>+     throw new ArgumentException ("sourceTable");
> >>+
> >>+ return Update (dataTable, tableMapping);
> >>  }
> >>
> >>  protected virtual void OnFillError (FillErrorEventArgs value)
> >>
> >
> >
> >
>
>
>