code: def get_last_sequence(self, cur=None):
          
          sql = 'SELECT sequence FROM {} ORDER BY sequence DESC LIMIT 1;'.format(self.subdomain_table)
          cursor = None
          if cur is None:
              cursor = self.conn.cursor()
          else:
              cursor = cur
  
          db_query_execute(cursor, sql, ())
          last_seq = None
          try:
              last_seq = cursor.fetchone()[0]
          except:
              last_seq = 0
          
          return int(last_seq)
docs: Get the highest sequence number in this db