diff -r 45c38bd3e96d -r 1913a3e8816a cubicweb/server/test/unittest_rql2sql.py
--- a/cubicweb/server/test/unittest_rql2sql.py	Wed Jun 01 17:04:33 2016 +0200
+++ b/cubicweb/server/test/unittest_rql2sql.py	Thu Sep 22 16:21:51 2016 +0200
@@ -1512,17 +1512,39 @@
 FROM cw_Affaire AS _T LEFT OUTER JOIN tags_relation AS rel_tags0 ON (rel_tags0.eid_to=_T.cw_eid) LEFT OUTER JOIN cw_Tag AS _TAG ON (rel_tags0.eid_from=_TAG.cw_eid AND _TAG.cw_name=t)
 GROUP BY _T.cw_eid) AS _T0 ON (_T1.C0=_T0.C0)'''),
 
+            ('''Any TT1,STD,STDD WHERE TT2 identity TT1?
+ WITH TT1,STDD BEING (Any T,SUM(TD) GROUPBY T WHERE T is Affaire, T duration TD, TAG? tags T, TAG name "t"),
+      TT2,STD BEING (Any T,SUM(TD) GROUPBY T WHERE T is Affaire, T duration TD)''',
+             '''SELECT _T0.C0, _T1.C1, _T0.C1
+FROM (SELECT _T.cw_eid AS C0, SUM(_T.cw_duration) AS C1
+FROM cw_Affaire AS _T
+GROUP BY _T.cw_eid) AS _T1 LEFT OUTER JOIN (SELECT _T.cw_eid AS C0, SUM(_T.cw_duration) AS C1
+FROM cw_Affaire AS _T LEFT OUTER JOIN tags_relation AS rel_tags0 ON (rel_tags0.eid_to=_T.cw_eid) LEFT OUTER JOIN cw_Tag AS _TAG ON (rel_tags0.eid_from=_TAG.cw_eid AND _TAG.cw_name=t)
+GROUP BY _T.cw_eid) AS _T0 ON (_T1.C0=_T0.C0)'''),
+
+            (''' Any X WHERE X eid >= 1200 WITH X BEING ((Any X WHERE X is CWUser) UNION (Any X WHERE X is CWGroup))''',
+             '''SELECT _T0.C0
+FROM ((SELECT _X.cw_eid AS C0
+FROM cw_CWUser AS _X)
+UNION ALL
+(SELECT _X.cw_eid AS C0
+FROM cw_CWGroup AS _X)) AS _T0
+WHERE _T0.C0>=1200'''),
+
         ]:
             with self.subTest(rql=rql):
                 self._check(rql, sql)
 
     def test_subquery_error(self):
-        rql = ('Any N WHERE X name N WITH X BEING '
-               '((Any X WHERE X is State)'
-               ' UNION '
-               ' (Any X WHERE X is Transition))')
-        rqlst = self._prepare(rql)
-        self.assertRaises(BadRQLQuery, self.o.generate, rqlst)
+        for rql in (
+                'Any N WHERE X name N WITH X BEING '
+                '((Any X WHERE X is State) UNION (Any X WHERE X is Transition))',
+
+                'Any X WHERE X modification_date >= TODAY WITH X BEING '
+                '((Any X WHERE X is CWUser) UNION (Any X WHERE X is CWGroup))''',
+        ):
+            rqlst = self._prepare(rql)
+            self.assertRaises(BadRQLQuery, self.o.generate, rqlst)
 
     def test_inline(self):
         for rql, sql in INLINE: