code: def __is_applied(self, delta):
          
  
          query = """
          SELECT id FROM {}
          WHERE version = '{}'
              AND checksum = '{}'
              AND success = 'TRUE'
          """.format(
              self.upgrades_table, delta.get_version(), delta.get_checksum())
  
          self.cursor.execute(query)
          if not self.cursor.fetchone():
              return False
          else:
              return True
docs: Verifies if delta file is already applied on database
  
          Parameters
          ----------
          delta: Delta object
              The delta object representing the delta file
  
          Returns
          -------
          bool
              True if the delta is already applied on the db
              False otherwise