code: protected function calculate()
      {
        // Determine Action
        $action = false;
        $actions = 0;
        if($this->delete) {
          $actions += 1;
          $action = 'DELETE';
        }
        if(!empty($this->inserts)) {
          $actions += 1;
          $action = 'INSERT';
        }
        if(!empty($this->updates)) {
          $actions += 1;
          $action = 'UPDATE';
        }
        if(!empty($this->selects)) {
          $actions += 1;
          $action = 'SELECT';
        }
        if(!empty($this->create)) {
          $actions += 1;
          $action = 'CREATE';
        }
        if ($actions > 1) {
          throw new \Exception("More than one query action specified! When using Cora's query builder class, only one type of query (select, update, delete, insert) can be done at a time.");
        }
        else {
            $calcMethod = 'calculate'.$action;
            $this->$calcMethod();
        }      
      }
docs: Create the SQL string from Database class raw data.