protected function queryScalar($selectExpression, $db)
    {
        /* @var $modelClass ActiveRecord */
        $modelClass = $this->modelClass;
        if ($db === null) {
            $db = $modelClass::getDb();
        }

        if ($this->sql === null) {
            return parent::queryScalar($selectExpression, $db);
        }

        $command = (new Query())->select([$selectExpression])
            ->from(['c' => "({$this->sql})"])
            ->params($this->params)
            ->createCommand($db);
        $this->setCommandCache($command);

        return $command->queryScalar();
    }
protected function queryScalar($selectExpression, $db)
    {
        
        $modelClass = $this->modelClass;
        if ($db === null) {
            $db = $modelClass::getDb();
        }

        if ($this->sql === null) {
            return parent::queryScalar($selectExpression, $db);
        }

        $command = (new Query())->select([$selectExpression])
            ->from(['c' => "({$this->sql})"])
            ->params($this->params)
            ->createCommand($db);
        $this->setCommandCache($command);

        return $command->queryScalar();
    }
protected function queryScalar ( $ selectExpression , $ db ) { /* @var $modelClass ActiveRecord */ $ modelClass = $ this -> modelClass ; if ( $ db === null ) { $ db = $ modelClass :: getDb ( ) ; } if ( $ this -> sql === null ) { return parent :: queryScalar ( $ selectExpression , $ db ) ; } $ command = ( new Query ( ) ) -> select ( [ $ selectExpression ] ) -> from ( [ 'c' => "({$this->sql})" ] ) -> params ( $ this -> params ) -> createCommand ( $ db ) ; $ this -> setCommandCache ( $ command ) ; return $ command -> queryScalar ( ) ; }
{@inheritdoc}
{