Commit b7fdd60d authored by Stewart Park's avatar Stewart Park Committed by Tim Graham
Browse files

Fixed #24675 -- Skipped SQL_AUTO_IS_NULL query on MySQL if not needed.

parent 3d223677

django/db/backends/mysql/base.py

+7 −6
Original line number Diff line number Diff line
@@ -267,11 +267,12 @@ class DatabaseWrapper(BaseDatabaseWrapper): 
        return conn



    def init_connection_state(self):

        if self.features.is_sql_auto_is_null_enabled:

            with self.cursor() as cursor:

            # SQL_AUTO_IS_NULL in MySQL controls whether an AUTO_INCREMENT column

            # on a recently-inserted row will return when the field is tested for

            # NULL.  Disabling this value brings this aspect of MySQL in line with

            # SQL standards.

                # SQL_AUTO_IS_NULL controls whether an AUTO_INCREMENT column on

                # a recently inserted row will return when the field is tested

                # for NULL. Disabling this brings this aspect of MySQL in line

                # with SQL standards.

                cursor.execute('SET SQL_AUTO_IS_NULL = 0')



    def create_cursor(self):

django/db/backends/mysql/features.py

+6 −0
Original line number Diff line number Diff line
@@ -69,3 +69,9 @@ class DatabaseFeatures(BaseDatabaseFeatures): 


    def introspected_boolean_field_type(self, *args, **kwargs):

        return 'IntegerField'



    @cached_property

    def is_sql_auto_is_null_enabled(self):

        with self.connection.cursor() as cursor:

            cursor.execute('SELECT @@SQL_AUTO_IS_NULL')

            return cursor.fetchone()[0] == 1

tests/backends/test_mysql.py

0 → 100644
+20 −0
Original line number Diff line number Diff line 
from __future__ import unicode_literals



import unittest



from django.db import connection

from django.test import TestCase, override_settings





@override_settings(DEBUG=True)

@unittest.skipUnless(connection.vendor == 'mysql', 'MySQL specific test.')

class MySQLTests(TestCase):



    def test_auto_is_null_auto_config(self):

        query = 'set sql_auto_is_null = 0'

        connection.init_connection_state()

        last_query = connection.queries[-1]['sql'].lower()

        if connection.features.is_sql_auto_is_null_enabled:

            self.assertIn(query, last_query)

        else:

            self.assertNotIn(query, last_query)