--- a/src/hdabo/migrations/0008_to_dbpedia_fr.py	Wed Jun 25 12:59:49 2014 +0200
+++ b/src/hdabo/migrations/0008_to_dbpedia_fr.py	Wed Jun 25 17:34:54 2014 +0200
@@ -71,7 +71,7 @@
                         
             if empty_after:
                 #print "3 : " + tag.label.encode("utf8")
-                tag.dbpedia_uri = ""
+                tag.dbpedia_uri = None
                 tag.save()