code: def searchExpressionLevelsInDb(
              self, rnaQuantId, names=[], threshold=0.0, startIndex=0,
              maxResults=0):
          
          sql = ("SELECT * FROM Expression WHERE "
                 "rna_quantification_id = ? "
                 "AND expression > ? ")
          sql_args = (rnaQuantId, threshold)
          if len(names) > 0:
              sql += "AND name in ("
              sql += ",".join(['?' for name in names])
              sql += ") "
              for name in names:
                  sql_args += (name,)
          sql += sqlite_backend.limitsSql(
              startIndex=startIndex, maxResults=maxResults)
          query = self._dbconn.execute(sql, sql_args)
          return sqlite_backend.iterativeFetch(query)
docs: :param rnaQuantId: string restrict search by quantification id
          :param threshold: float minimum expression values to return
          :return an array of dictionaries, representing the returned data.