Moved EmpytResultSet to django.core.exceptions.

This removes the need for some inner imports.

4 files changed, 5 insertions, 8 deletions

diff --git a/django/db/models/sql/__init__.py b/django/db/models/sql/__init__.py
index 80c12584fd..31f45eb90d 100644
--- a/django/db/models/sql/__init__.py
+++ b/django/db/models/sql/__init__.py
@@ -1,4 +1,4 @@
-from django.db.models.sql.datastructures import EmptyResultSet
+from django.core.exceptions import EmptyResultSet
 from django.db.models.sql.query import *  # NOQA
 from django.db.models.sql.subqueries import *  # NOQA
 from django.db.models.sql.where import AND, OR
diff --git a/django/db/models/sql/compiler.py b/django/db/models/sql/compiler.py
index 0b7f9e20cb..cedb140143 100644
--- a/django/db/models/sql/compiler.py
+++ b/django/db/models/sql/compiler.py
@@ -1,14 +1,13 @@
 import re
 from itertools import chain
 
-from django.core.exceptions import FieldError
+from django.core.exceptions import EmptyResultSet, FieldError
 from django.db.models.constants import LOOKUP_SEP
 from django.db.models.expressions import OrderBy, Random, RawSQL, Ref
 from django.db.models.query_utils import QueryWrapper, select_related_descend
 from django.db.models.sql.constants import (
     CURSOR, GET_ITERATOR_CHUNK_SIZE, MULTI, NO_RESULTS, ORDER_DIR, SINGLE,
 )
-from django.db.models.sql.datastructures import EmptyResultSet
 from django.db.models.sql.query import Query, get_order_dir
 from django.db.transaction import TransactionManagementError
 from django.db.utils import DatabaseError
diff --git a/django/db/models/sql/datastructures.py b/django/db/models/sql/datastructures.py
index 42f2d8790d..02e4f930e1 100644
--- a/django/db/models/sql/datastructures.py
+++ b/django/db/models/sql/datastructures.py
@@ -2,13 +2,11 @@
 Useful auxiliary data structures for query construction. Not useful outside
 the SQL domain.
 """
+# for backwards-compatibility in Django 1.11
+from django.core.exceptions import EmptyResultSet  # NOQA: F401
 from django.db.models.sql.constants import INNER, LOUTER
 
 
-class EmptyResultSet(Exception):
-    pass
-
-
 class MultiJoin(Exception):
     """
     Used by join construction code to indicate the point at which a
diff --git a/django/db/models/sql/where.py b/django/db/models/sql/where.py
index 9836da8735..c70d34f94f 100644
--- a/django/db/models/sql/where.py
+++ b/django/db/models/sql/where.py
@@ -2,7 +2,7 @@
 Code to manage the creation and SQL rendering of 'where' constraints.
 """
 
-from django.db.models.sql.datastructures import EmptyResultSet
+from django.core.exceptions import EmptyResultSet
 from django.utils import tree
 from django.utils.functional import cached_property