code: public function queryScalar()
      {
          $result = $this->queryInternal('fetchColumn', 0);
          if (is_resource($result) && get_resource_type($result) === 'stream') {
              return stream_get_contents($result);
          }
  
          return $result;
      }
docs: Executes the SQL statement and returns the value of the first column in the first row of data.
  This method is best used when only a single value is needed for a query.
  @return string|null|false the value of the first column in the first row of the query result.
  False is returned if there is no value.
  @throws Exception execution failed