code: def getExpressionLevelById(self, expressionId):
          
          sql = ("SELECT * FROM Expression WHERE id = ?")
          query = self._dbconn.execute(sql, (expressionId,))
          try:
              return sqlite_backend.fetchOne(query)
          except AttributeError:
              raise exceptions.ExpressionLevelNotFoundException(
                  expressionId)
docs: :param expressionId: the ExpressionLevel ID
          :return: dictionary representing an ExpressionLevel object,
              or None if no match is found.