Commit f3c0cb01 authored by Shai Berger's avatar Shai Berger
Browse files

[1.7.x] Fixed #23061: Avoided setting a limit on a query for get with select_for_update on Oracle 

Thanks Michael Miller for reporting the issue.

Backport of 746f2a4b from master
parent a582431b

django/db/backends/__init__.py

+3 −0
Original line number Diff line number Diff line
@@ -755,6 +755,9 @@ class BaseDatabaseFeatures(object): 


    uppercases_column_names = False



    # Does the backend support "select for update" queries with limit (and offset)?

    supports_select_for_update_with_limit = True



    def __init__(self, connection):

        self.connection = connection

django/db/backends/oracle/base.py

+2 −0
Original line number Diff line number Diff line
@@ -120,6 +120,8 @@ class DatabaseFeatures(BaseDatabaseFeatures): 
    closed_cursor_error_class = InterfaceError

    bare_select_suffix = " FROM DUAL"

    uppercases_column_names = True

    # select for update with limit can be achieved on Oracle, but not with the current backend.

    supports_select_for_update_with_limit = False





class DatabaseOperations(BaseDatabaseOperations):

django/db/models/query.py

+3 −1
Original line number Diff line number Diff line
@@ -345,6 +345,8 @@ class QuerySet(object): 
        clone = self.filter(*args, **kwargs)

        if self.query.can_filter():

            clone = clone.order_by()

        if (not clone.query.select_for_update or

            connections[self.db].features.supports_select_for_update_with_limit):

            clone = clone[:MAX_GET_RESULTS + 1]

        num = len(clone)

        if num == 1:

tests/select_for_update/tests.py

+6 −0
Original line number Diff line number Diff line
@@ -292,3 +292,9 @@ class SelectForUpdateTests(TransactionTestCase): 
            self.assertEqual(router.db_for_write(Person), query.db)

        finally:

            router.routers = old_routers



    @skipUnlessDBFeature('has_select_for_update')

    def test_select_for_update_with_get(self):

        with transaction.atomic():

            person = Person.objects.select_for_update().get(name='Reinhardt')

        self.assertEqual(person.name, 'Reinhardt')