Fixed #31479 -- Added support to reset sequences on SQLite.

4 files changed, 40 insertions, 7 deletions

diff --git a/django/db/backends/sqlite3/features.py b/django/db/backends/sqlite3/features.py
index 84eca98644..817b1067e3 100644
--- a/django/db/backends/sqlite3/features.py
+++ b/django/db/backends/sqlite3/features.py
@@ -26,7 +26,6 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     supports_atomic_references_rename = Database.sqlite_version_info >= (3, 26, 0)
     can_create_inline_fk = False
     supports_paramstyle_pyformat = False
-    supports_sequence_reset = False
     can_clone_databases = True
     supports_temporal_subtraction = True
     ignores_table_name_case = True
diff --git a/django/db/backends/sqlite3/operations.py b/django/db/backends/sqlite3/operations.py
index 3f55332c99..9510b5edd9 100644
--- a/django/db/backends/sqlite3/operations.py
+++ b/django/db/backends/sqlite3/operations.py
@@ -201,13 +201,33 @@ class DatabaseOperations(BaseDatabaseOperations):
             # Simulate TRUNCATE CASCADE by recursively collecting the tables
             # referencing the tables to be flushed.
             tables = set(chain.from_iterable(self._references_graph(table) for table in tables))
-        # Note: No requirement for reset of auto-incremented indices (cf. other
-        # sql_flush() implementations). Just return SQL at this point
-        return ['%s %s %s;' % (
+        sql = ['%s %s %s;' % (
             style.SQL_KEYWORD('DELETE'),
             style.SQL_KEYWORD('FROM'),
             style.SQL_FIELD(self.quote_name(table))
         ) for table in tables]
+        if reset_sequences:
+            sequences = [{'table': table} for table in tables]
+            sql.extend(self.sequence_reset_by_name_sql(style, sequences))
+        return sql
+
+    def sequence_reset_by_name_sql(self, style, sequences):
+        if not sequences:
+            return []
+        return [
+            '%s %s %s %s = 0 %s %s %s (%s);' % (
+                style.SQL_KEYWORD('UPDATE'),
+                style.SQL_TABLE(self.quote_name('sqlite_sequence')),
+                style.SQL_KEYWORD('SET'),
+                style.SQL_FIELD(self.quote_name('seq')),
+                style.SQL_KEYWORD('WHERE'),
+                style.SQL_FIELD(self.quote_name('name')),
+                style.SQL_KEYWORD('IN'),
+                ', '.join([
+                    "'%s'" % sequence_info['table'] for sequence_info in sequences
+                ]),
+            ),
+        ]
 
     def adapt_datetimefield_value(self, value):
         if value is None:
diff --git a/docs/releases/3.1.txt b/docs/releases/3.1.txt
index 4cf8183d4b..ceb1b0f0bf 100644
--- a/docs/releases/3.1.txt
+++ b/docs/releases/3.1.txt
@@ -320,6 +320,9 @@ Management Commands
 * The new :option:`dbshell -- ARGUMENTS <dbshell -->` option allows passing
   extra arguments to the command-line client for the database.
 
+* The :djadmin:`flush` and :djadmin:`sqlflush` commands now include SQL to
+  reset sequences on SQLite.
+
 Migrations
 ~~~~~~~~~~
 
diff --git a/tests/backends/sqlite/test_operations.py b/tests/backends/sqlite/test_operations.py
index 0ee70061f8..863a978580 100644
--- a/tests/backends/sqlite/test_operations.py
+++ b/tests/backends/sqlite/test_operations.py
@@ -40,7 +40,6 @@ class SQLiteOperationsTests(TestCase):
         )
 
     def test_sql_flush_sequences(self):
-        # sequences doesn't change statements on SQLite.
         self.assertEqual(
             connection.ops.sql_flush(
                 no_style(),
@@ -50,11 +49,12 @@ class SQLiteOperationsTests(TestCase):
             [
                 'DELETE FROM "backends_person";',
                 'DELETE FROM "backends_tag";',
+                'UPDATE "sqlite_sequence" SET "seq" = 0 WHERE "name" IN '
+                '(\'backends_person\', \'backends_tag\');',
             ],
         )
 
     def test_sql_flush_sequences_allow_cascade(self):
-        # sequences doesn't change statements on SQLite.
         statements = connection.ops.sql_flush(
             no_style(),
             [Person._meta.db_table, Tag._meta.db_table],
@@ -63,7 +63,7 @@ class SQLiteOperationsTests(TestCase):
         )
         self.assertEqual(
             # The tables are processed in an unordered set.
-            sorted(statements),
+            sorted(statements[:-1]),
             [
                 'DELETE FROM "backends_person";',
                 'DELETE FROM "backends_tag";',
@@ -72,3 +72,14 @@ class SQLiteOperationsTests(TestCase):
                 'zzzzzzzzzzzzzzzzzzzzzzz";',
             ],
         )
+        self.assertIs(statements[-1].startswith(
+            'UPDATE "sqlite_sequence" SET "seq" = 0 WHERE "name" IN ('
+        ), True)
+        self.assertIn("'backends_person'", statements[-1])
+        self.assertIn("'backends_tag'", statements[-1])
+        self.assertIn(
+            "'backends_verylongmodelnamezzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
+            "zzzz_m2m_also_quite_long_zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
+            "zzz'",
+            statements[-1],
+        )