Index: openacs-4/packages/categories/tcl/categories-procs.xql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/categories/tcl/categories-procs.xql,v
diff -u -r1.7 -r1.8
--- openacs-4/packages/categories/tcl/categories-procs.xql	16 Feb 2005 02:43:15 -0000	1.7
+++ openacs-4/packages/categories/tcl/categories-procs.xql	23 Mar 2005 22:44:56 -0000	1.8
@@ -38,8 +38,11 @@
       <querytext>
       
 			insert into category_object_map (category_id, object_id)
-			values (:category_id, :object_id)
-		    
+			select :category_id, :object_id
+                        where not exists (select 1
+                                          from category_object_map
+                                          where category_id = :category_id
+                                            and object_id = :object_id);
       </querytext>
 </fullquery>