Fixed #31473 -- Made sql_flush() use RESTART IDENTITY to reset sequences on PostgreSQL.

The sql_flush() positional argument sequences is replaced by the boolean
keyword-only argument reset_sequences. This ensures that the old
function signature can't be used by mistake when upgrading Django. When
the new argument is True, the sequences of the truncated tables will
reset. Using a single boolean value, rather than a list, allows making a
binary yes/no choice as to whether to reset all sequences rather than a
working on a completely different set.

1 files changed, 16 insertions, 31 deletions

diff --git a/tests/backends/mysql/test_operations.py b/tests/backends/mysql/test_operations.py
index f1d9342a7b..a98e8963b7 100644
--- a/tests/backends/mysql/test_operations.py
+++ b/tests/backends/mysql/test_operations.py
@@ -4,7 +4,7 @@ from django.core.management.color import no_style
 from django.db import connection
 from django.test import SimpleTestCase
 
-from ..models import Person, Square, Tag
+from ..models import Person, Tag
 
 
 @unittest.skipUnless(connection.vendor == 'mysql', 'MySQL tests.')
@@ -13,50 +13,35 @@ class MySQLOperationsTests(SimpleTestCase):
         # allow_cascade doesn't change statements on MySQL.
         for allow_cascade in [False, True]:
             with self.subTest(allow_cascade=allow_cascade):
-                statements = connection.ops.sql_flush(
-                    no_style(),
-                    [Person._meta.db_table, Tag._meta.db_table],
-                    [],
-                    allow_cascade=allow_cascade,
-                )
-                self.assertEqual(statements[0], 'SET FOREIGN_KEY_CHECKS = 0;')
-                # The tables are processed in an unordered set.
                 self.assertEqual(
-                    sorted(statements[1:-1]),
+                    connection.ops.sql_flush(
+                        no_style(),
+                        [Person._meta.db_table, Tag._meta.db_table],
+                        allow_cascade=allow_cascade,
+                    ),
                     [
+                        'SET FOREIGN_KEY_CHECKS = 0;',
                         'DELETE FROM `backends_person`;',
                         'DELETE FROM `backends_tag`;',
+                        'SET FOREIGN_KEY_CHECKS = 1;',
                     ],
                 )
-                self.assertEqual(statements[-1], 'SET FOREIGN_KEY_CHECKS = 1;')
 
     def test_sql_flush_sequences(self):
         # allow_cascade doesn't change statements on MySQL.
         for allow_cascade in [False, True]:
             with self.subTest(allow_cascade=allow_cascade):
-                statements = connection.ops.sql_flush(
-                    no_style(),
-                    [Person._meta.db_table, Square._meta.db_table, Tag._meta.db_table],
-                    [
-                        {
-                            'table': Person._meta.db_table,
-                            'column': Person._meta.pk.db_column,
-                        },
-                        {
-                            'table': Tag._meta.db_table,
-                            'column': Tag._meta.pk.db_column,
-                        },
-                    ],
-                    allow_cascade=allow_cascade,
-                )
-                self.assertEqual(statements[0], 'SET FOREIGN_KEY_CHECKS = 0;')
-                # The tables are processed in an unordered set.
                 self.assertEqual(
-                    sorted(statements[1:-1]),
+                    connection.ops.sql_flush(
+                        no_style(),
+                        [Person._meta.db_table, Tag._meta.db_table],
+                        reset_sequences=True,
+                        allow_cascade=allow_cascade,
+                    ),
                     [
-                        'DELETE FROM `backends_square`;',
+                        'SET FOREIGN_KEY_CHECKS = 0;',
                         'TRUNCATE `backends_person`;',
                         'TRUNCATE `backends_tag`;',
+                        'SET FOREIGN_KEY_CHECKS = 1;',
                     ],
                 )
-                self.assertEqual(statements[-1], 'SET FOREIGN_KEY_CHECKS = 1;')