text: from django.db import utils
  from django.db.backends.base.features import BaseDatabaseFeatures
  from django.utils.functional import cached_property
  
  
  class DatabaseFeatures(BaseDatabaseFeatures):
      # SQLite can read from a cursor since SQLite 3.6.5, subject to the caveat
      # that statements within a connection aren't isolated from each other. See
      # https://sqlite.org/isolation.html.
      can_use_chunked_reads = True
      test_db_allows_multiple_connections = False
      supports_unspecified_pk = True
      supports_timezones = False
      max_query_params = 999
      supports_mixed_date_datetime_comparisons = False
      autocommits_when_autocommit_is_off = True
      can_introspect_decimal_field = False
      can_introspect_duration_field = False
      can_introspect_positive_integer_field = True
      can_introspect_small_integer_field = True
      supports_transactions = True
      atomic_transactions = False
      can_rollback_ddl = True
      supports_atomic_references_rename = False
      supports_paramstyle_pyformat = False
      supports_sequence_reset = False
      can_clone_databases = True
      supports_temporal_subtraction = True
      ignores_table_name_case = True
      supports_cast_with_precision = False
      time_cast_precision = 3
      uses_savepoints = True
      can_release_savepoints = True
  
      @cached_property
      def supports_stddev(self):
          """
          Confirm support for STDDEV and related stats functions.
  
          SQLite supports STDDEV as an extension package; so
          connection.ops.check_expression_support() can't unilaterally
          rule out support for STDDEV. Manually check whether the call works.
          """
          with self.connection.cursor() as cursor:
              cursor.execute('CREATE TABLE STDDEV_TEST (X INT)')
              try:
                  cursor.execute('SELECT STDDEV(*) FROM STDDEV_TEST')
                  has_support = True
              except utils.DatabaseError:
                  has_support = False
              cursor.execute('DROP TABLE STDDEV_TEST')
          return has_support
  