Removed EverythingNode

At the same time, made sure that empty nodes in where clause match
everything.

django/db/models/fields/related.py

@@ -1767,6 +1767,7 @@ class ForeignObject(RelatedField):
             root_constraint.add(lookup_class(targets[0].get_col(alias, sources[0]), value), AND)
         elif lookup_type == 'in':
             values = [get_normalized_value(value) for value in raw_value]
+            root_constraint.connector = OR
             for value in values:
                 value_constraint = constraint_class()
                 for source, target, val in zip(sources, targets, value):

django/db/models/sql/query.py

@@ -24,8 +24,8 @@ from django.db.models.sql.constants import (QUERY_TERMS, ORDER_DIR, SINGLE,
         ORDER_PATTERN, INNER, LOUTER)
 from django.db.models.sql.datastructures import (
     EmptyResultSet, Empty, MultiJoin, Join, BaseTable)
-from django.db.models.sql.where import (WhereNode, EverythingNode,
+from django.db.models.sql.where import (WhereNode, ExtraWhere, AND, OR,
-    ExtraWhere, AND, OR, NothingNode)
+        NothingNode)
 from django.utils import six
 from django.utils.deprecation import RemovedInDjango20Warning
 from django.utils.encoding import force_text
@@ -526,20 +526,8 @@ class Query(object):
 
         # Now relabel a copy of the rhs where-clause and add it to the current
         # one.
-        if rhs.where:
         w = rhs.where.clone()
         w.relabel_aliases(change_map)
-            if not self.where:
-                # Since 'self' matches everything, add an explicit "include
-                # everything" where-constraint so that connections between the
-                # where clauses won't exclude valid results.
-                self.where.add(EverythingNode(), AND)
-        elif self.where:
-            # rhs has an empty where clause.
-            w = self.where_class()
-            w.add(EverythingNode(), AND)
-        else:
-            w = self.where_class()
         self.where.add(w, connector)
 
         # Selection columns and extra extensions are those provided by 'rhs'.
@@ -1207,7 +1195,8 @@ class Query(object):
         # So, demotion is OK.
         existing_inner = set(
             (a for a in self.alias_map if self.alias_map[a].join_type == INNER))
-        clause, require_inner = self._add_q(q_object, self.used_aliases)
+        clause, _ = self._add_q(q_object, self.used_aliases)
+        if clause:
             self.where.add(clause, AND)
         self.demote_joins(existing_inner)
 
@@ -1233,6 +1222,7 @@ class Query(object):
                     child, can_reuse=used_aliases, branch_negated=branch_negated,
                     current_negated=current_negated, connector=connector, allow_joins=allow_joins)
                 joinpromoter.add_votes(needed_inner)
+            if child_clause:
                 target_clause.add(child_clause, connector)
         needed_inner = joinpromoter.update_join_types(self)
         return target_clause, needed_inner

django/db/models/sql/where.py

@@ -28,22 +28,22 @@ class WhereNode(tree.Node):
     the correct SQL).
 
     A child is usually an expression producing boolean values. Most likely the
-    expression is a Lookup instance, but other types of objects fulfilling the
+    expression is a Lookup instance.
-    required API could be used too (for example, sql.where.EverythingNode).
 
     However, a child could also be any class with as_sql() and either
-    relabeled_clone() method or relabel_aliases() and clone() methods. The
+    relabeled_clone() method or relabel_aliases() and clone() methods and
-    second alternative should be used if the alias is not the only mutable
+    contains_aggregate attribute.
-    variable.
     """
     default = AND
 
     def split_having(self, negated=False):
         """
         Returns two possibly None nodes: one for those parts of self that
-        should be pushed to having and one for those parts of self
+        should be included in the WHERE clause and one for those parts of
-        that should be in where.
+        self that must be included in the HAVING clause.
         """
+        if not self.contains_aggregate:
+            return self, None
         in_negated = negated ^ self.negated
         # If the effective connector is OR and this node contains an aggregate,
         # then we need to push the whole branch to HAVING clause.
@@ -57,9 +57,9 @@ class WhereNode(tree.Node):
         for c in self.children:
             if hasattr(c, 'split_having'):
                 where_part, having_part = c.split_having(in_negated)
-                if where_part:
+                if where_part is not None:
                     where_parts.append(where_part)
-                if having_part:
+                if having_part is not None:
                     having_parts.append(having_part)
             elif c.contains_aggregate:
                 having_parts.append(c)
@@ -76,55 +76,39 @@ class WhereNode(tree.Node):
         None, [] if this node is empty, and raises EmptyResultSet if this
         node can't match anything.
         """
-        # Note that the logic here is made slightly more complex than
-        # necessary because there are two kind of empty nodes: Nodes
-        # containing 0 children, and nodes that are known to match everything.
-        # A match-everything node is different than empty node (which also
-        # technically matches everything) for backwards compatibility reasons.
-        # Refs #5261.
         result = []
         result_params = []
-        everything_childs, nothing_childs = 0, 0
+        if self.connector == AND:
-        non_empty_childs = len(self.children)
+            full_needed, empty_needed = len(self.children), 1
+        else:
+            full_needed, empty_needed = 1, len(self.children)
 
         for child in self.children:
             try:
                 sql, params = compiler.compile(child)
             except EmptyResultSet:
-                nothing_childs += 1
+                empty_needed -= 1
             else:
                 if sql:
                     result.append(sql)
                     result_params.extend(params)
                 else:
-                    if sql is None:
+                    full_needed -= 1
-                        # Skip empty childs totally.
-                        non_empty_childs -= 1
-                        continue
-                    everything_childs += 1
             # Check if this node matches nothing or everything.
             # First check the amount of full nodes and empty nodes
             # to make this node empty/full.
-            if self.connector == AND:
-                full_needed, empty_needed = non_empty_childs, 1
-            else:
-                full_needed, empty_needed = 1, non_empty_childs
             # Now, check if this node is full/empty using the
             # counts.
-            if empty_needed - nothing_childs <= 0:
+            if empty_needed == 0:
                 if self.negated:
                     return '', []
                 else:
                     raise EmptyResultSet
-            if full_needed - everything_childs <= 0:
+            if full_needed == 0:
                 if self.negated:
                     raise EmptyResultSet
                 else:
                     return '', []
-
-        if non_empty_childs == 0:
-            # All the child nodes were empty, so this one is empty, too.
-            return None, []
         conn = ' %s ' % self.connector
         sql_string = conn.join(result)
         if sql_string:
@@ -186,16 +170,6 @@ class WhereNode(tree.Node):
         return self._contains_aggregate(self)
 
 
-class EverythingNode(object):
-    """
-    A node that matches everything.
-    """
-    contains_aggregate = False
-
-    def as_sql(self, compiler=None, connection=None):
-        return '', []
-
-
 class NothingNode(object):
     """
     A node that matches nothing.

tests/queries/tests.py

@@ -9,7 +9,7 @@ import unittest
 from django.core.exceptions import FieldError
 from django.db import connection, DEFAULT_DB_ALIAS
 from django.db.models import Count, F, Q
-from django.db.models.sql.where import WhereNode, EverythingNode, NothingNode
+from django.db.models.sql.where import WhereNode, NothingNode
 from django.db.models.sql.constants import LOUTER
 from django.db.models.sql.datastructures import EmptyResultSet
 from django.test import TestCase, skipUnlessDBFeature
@@ -2851,20 +2851,10 @@ class WhereNodeTest(TestCase):
 
     def test_empty_full_handling_conjunction(self):
         compiler = WhereNodeTest.MockCompiler()
-        w = WhereNode(children=[EverythingNode()])
-        self.assertEqual(w.as_sql(compiler, connection), ('', []))
-        w.negate()
-        self.assertRaises(EmptyResultSet, w.as_sql, compiler, connection)
         w = WhereNode(children=[NothingNode()])
         self.assertRaises(EmptyResultSet, w.as_sql, compiler, connection)
         w.negate()
         self.assertEqual(w.as_sql(compiler, connection), ('', []))
-        w = WhereNode(children=[EverythingNode(), EverythingNode()])
-        self.assertEqual(w.as_sql(compiler, connection), ('', []))
-        w.negate()
-        self.assertRaises(EmptyResultSet, w.as_sql, compiler, connection)
-        w = WhereNode(children=[EverythingNode(), self.DummyNode()])
-        self.assertEqual(w.as_sql(compiler, connection), ('dummy', []))
         w = WhereNode(children=[self.DummyNode(), self.DummyNode()])
         self.assertEqual(w.as_sql(compiler, connection), ('(dummy AND dummy)', []))
         w.negate()
@@ -2876,22 +2866,10 @@ class WhereNodeTest(TestCase):
 
     def test_empty_full_handling_disjunction(self):
         compiler = WhereNodeTest.MockCompiler()
-        w = WhereNode(children=[EverythingNode()], connector='OR')
-        self.assertEqual(w.as_sql(compiler, connection), ('', []))
-        w.negate()
-        self.assertRaises(EmptyResultSet, w.as_sql, compiler, connection)
         w = WhereNode(children=[NothingNode()], connector='OR')
         self.assertRaises(EmptyResultSet, w.as_sql, compiler, connection)
         w.negate()
         self.assertEqual(w.as_sql(compiler, connection), ('', []))
-        w = WhereNode(children=[EverythingNode(), EverythingNode()], connector='OR')
-        self.assertEqual(w.as_sql(compiler, connection), ('', []))
-        w.negate()
-        self.assertRaises(EmptyResultSet, w.as_sql, compiler, connection)
-        w = WhereNode(children=[EverythingNode(), self.DummyNode()], connector='OR')
-        self.assertEqual(w.as_sql(compiler, connection), ('', []))
-        w.negate()
-        self.assertRaises(EmptyResultSet, w.as_sql, compiler, connection)
         w = WhereNode(children=[self.DummyNode(), self.DummyNode()], connector='OR')
         self.assertEqual(w.as_sql(compiler, connection), ('(dummy OR dummy)', []))
         w.negate()
@@ -2905,15 +2883,20 @@ class WhereNodeTest(TestCase):
         compiler = WhereNodeTest.MockCompiler()
         empty_w = WhereNode()
         w = WhereNode(children=[empty_w, empty_w])
-        self.assertEqual(w.as_sql(compiler, connection), (None, []))
+        self.assertEqual(w.as_sql(compiler, connection), ('', []))
         w.negate()
-        self.assertEqual(w.as_sql(compiler, connection), (None, []))
+        with self.assertRaises(EmptyResultSet):
+            w.as_sql(compiler, connection)
         w.connector = 'OR'
-        self.assertEqual(w.as_sql(compiler, connection), (None, []))
+        with self.assertRaises(EmptyResultSet):
+            w.as_sql(compiler, connection)
         w.negate()
-        self.assertEqual(w.as_sql(compiler, connection), (None, []))
+        self.assertEqual(w.as_sql(compiler, connection), ('', []))
         w = WhereNode(children=[empty_w, NothingNode()], connector='OR')
-        self.assertRaises(EmptyResultSet, w.as_sql, compiler, connection)
+        self.assertEqual(w.as_sql(compiler, connection), ('', []))
+        w = WhereNode(children=[empty_w, NothingNode()], connector='AND')
+        with self.assertRaises(EmptyResultSet):
+            w.as_sql(compiler, connection)
 
 
 class IteratorExceptionsTest(TestCase):