enhance bad rql query detection with ordered distinct

We actually can't use distinct if an attribute is selected  and we sort
on another attribute

ChangeLog

 ChangeLog for RQL
 =================
 
+--
+    * enhance bad rql query detection with ordered distinct (can't use distinct
+      if an attribute is selected and we order on another attribute)
+
 2010-08-02  --  0.26.5
     * fix solutions computation crash with some query using sub-queries (closes #37423)
 

stcheck.py

@@ -162,8 +162,9 @@
                 self._check_selected(group, 'group', state)
         if node.distinct and node.orderby:
             # check that variables referenced in the given term are reachable from
-            # a selected variable with only ?1 cardinalityselected
-            selectidx = frozenset(vref.name for term in selected for vref in term.get_nodes(VariableRef))
+            # a selected variable with only ?1 cardinality selected
+            selectidx = frozenset(vref.name for term in selected
+                                  for vref in term.get_nodes(VariableRef))
             schema = self.schema
             for sortterm in node.orderby:
                 for vref in sortterm.term.get_nodes(VariableRef):
@@ -186,5 +187,5 @@
         path = has_path(graph, fromvar, tovar)
         if path is None:
             return False
-        for tovar in path:
+        for var in path:
             try:
@@ -190,4 +191,4 @@
             try:
-                rtype = graph[(fromvar, tovar)]
+                rtype = graph[(fromvar, var)]
                 cardidx = 0
             except KeyError:
@@ -192,7 +193,7 @@
                 cardidx = 0
             except KeyError:
-                rtype = graph[(tovar, fromvar)]
+                rtype = graph[(var, fromvar)]
                 cardidx = 1
             rschema = self.schema.rschema(rtype)
             for rdef in rschema.rdefs.itervalues():
                 # XXX aggregats handling needs much probably some enhancements...
@@ -195,7 +196,8 @@
                 cardidx = 1
             rschema = self.schema.rschema(rtype)
             for rdef in rschema.rdefs.itervalues():
                 # XXX aggregats handling needs much probably some enhancements...
-                if not (tovar in select.aggregated
-                        or rdef.cardinality[cardidx] in '?1'):
+                if not (var in select.aggregated
+                        or (rdef.cardinality[cardidx] in '?1' and
+                            (var == tovar or not rschema.final))):
                     return False
@@ -201,5 +203,5 @@
                     return False
-            fromvar = tovar
+            fromvar = var
         return True
 
 

test/unittest_analyze.py

@@ -47,7 +47,7 @@
         self.inlined = False
         if card is None:
             if self.final:
-                card = '?*'
+                card = '?1'
             else:
                 card = '**'
         self.card = card

test/unittest_stcheck.py

@@ -52,5 +52,8 @@
 
     'Any X WHERE X name "Toto", P is Person',
 
-    # BAD QUERY cant sort on y
+    "Any X WHERE X eid 0, X eid 1",
+
+    # DISTINCT+ORDERBY tests ###################################################
+    # cant sort on Y, B <- work_for X is multivalued
     'DISTINCT Any X ORDERBY Y WHERE B work_for X, B name Y',
@@ -56,6 +59,10 @@
     'DISTINCT Any X ORDERBY Y WHERE B work_for X, B name Y',
-
-    "Any X WHERE X eid 0, X eid 1"
+    # cant sort on PN, there may be different PF values for the same PN value
+    # XXX untrue if PF or PN is marked as unique
+    'DISTINCT Any PF ORDERBY PN WHERE P firstname PF, P name PN',
+    # cant sort on XN, there may be different PF values for the same PF value
+    'DISTINCT Any PF ORDERBY X WHERE P work_for X, P firstname PF',
+    'DISTINCT Any PF ORDERBY XN WHERE P work_for X, P firstname PF, X name XN',
 
     )
 
@@ -66,5 +73,6 @@
 
     'DISTINCT Any X, MAX(Y) GROUPBY X WHERE X is Person, Y is Company',
 
+    # DISTINCT+ORDERBY tests ###################################################
     # sorting allowed since order variable reachable from a selected
     # variable with only ?1 cardinality
@@ -69,5 +77,5 @@
     # sorting allowed since order variable reachable from a selected
     # variable with only ?1 cardinality
-    'DISTINCT Any B ORDERBY Y WHERE B work_for X, B name Y',
-    'DISTINCT Any B ORDERBY Y WHERE B work_for X, X name Y',
+    'DISTINCT Any P ORDERBY PN WHERE P work_for X, P name PN',
+    'DISTINCT Any P ORDERBY XN WHERE P work_for X, X name XN',
 
@@ -73,5 +81,4 @@
 
-#    'DISTINCT Any X ORDERBY SN WHERE X in_state S, S name SN',
 
 
     )