Added persistence support for Eiffel sqlite3 wrapper.

Updated existing persistency solution to be more generic to any db solution.

modules/blog/cms_node_storage_sql_blog_extension.e

@@ -83,11 +83,11 @@ feature -- Persistence
 
 				if l_update then
 					if l_has_modif then
-						sql_change (sql_update_node_data, l_parameters)
+						sql_modify (sql_update_node_data, l_parameters)
 					end
 				else
 					if l_has_modif then
-						sql_change (sql_insert_node_data, l_parameters)
+						sql_insert (sql_insert_node_data, l_parameters)
 					else
 						-- no page data, means everything is empty.
 						-- FOR NOW: always record row
@@ -116,7 +116,7 @@ feature -- Persistence
 			if a_node.has_id then
 				create l_parameters.make (1)
 				l_parameters.put (a_node.id, "nid")
-				sql_change (sql_delete_node_data, l_parameters)
+				sql_modify (sql_delete_node_data, l_parameters)
 			end
 		end
 
@@ -136,18 +136,21 @@ feature {NONE} -- Implementation
 			l_parameters.put (a_node.revision, "revision")
 			sql_query (sql_select_node_data, l_parameters)
 			if not has_error then
-				n := sql_rows_count
-				if n = 1 then
+				if not sql_after then
 						-- nid, revision, tags
 					l_rev := sql_read_integer_64 (2)
 					l_tags := sql_read_string_32 (3)
 					if l_tags /= Void then
 						Result := [l_rev, l_tags]
 					end
-				else
-					check unique_data: n = 0 end
+					sql_forth
+					if not sql_after then
+						check unique_data: n = 0 end
+						Result := Void
+					end
 				end
 			end
+			sql_finalize
 		ensure
 			accepted_revision: Result /= Void implies Result.revision <= a_node.revision
 		end