glom r1879 - in trunk: . glom/utility_widgets/db_adddel

[arminb svn gnome org]

Author: arminb
Date: Thu Feb  5 17:39:15 2009
New Revision: 1879
URL: http://svn.gnome.org/viewvc/glom?rev=1879&view=rev

Log:
2009-02-05  Armin Burgmeier  <armin openismus com>

	* glom/utility_widgets/db_adddel/glom_db_treemodel.cc: Added a
	clarifying comment on why we use a DataAccessWrapper.


Modified:
   trunk/ChangeLog
   trunk/glom/utility_widgets/db_adddel/glom_db_treemodel.cc

Modified: trunk/glom/utility_widgets/db_adddel/glom_db_treemodel.cc
==============================================================================
--- trunk/glom/utility_widgets/db_adddel/glom_db_treemodel.cc	(original)
+++ trunk/glom/utility_widgets/db_adddel/glom_db_treemodel.cc	Thu Feb  5 17:39:15 2009
@@ -482,7 +482,16 @@
     {
       //Specify the STATEMENT_MODEL_CURSOR, so that libgda only gets the rows that we actually use.
       m_gda_datamodel = m_connection->get_gda_connection()->statement_execute_select(stmt, Gnome::Gda::STATEMENT_MODEL_CURSOR_FORWARD);
-      // Use a DataAccessWrapper to allow random access: 
+
+      // Use a DataAccessWrapper to allow random access. This is necessary
+      // since we use move_to_row() on a created iterator in
+      // fill_values_if_necessary(), which does not work if the iterator
+      // does not support it (for example the one for Sqlite recordsets does
+      // not). The alternative would be to acquire a random-access model
+      // directly here for SQLite, but this would
+      // a) make this code dependent on the database backend used
+      // b) fetch rows we perhaps don't need, if only the first few rows of
+      // a table are accessed.
       m_gda_datamodel = Gnome::Gda::DataAccessWrapper::create(m_gda_datamodel);
 
       if(app && app->get_show_sql_debug())