public function deriveColumn($index)
    {
        $this->validateColumnIndex($index);
        
        $column = new DerivedColumn($this->columns[$index]->getAlias());
        
        return $column->setTable($this);
    }
public function deriveColumn($index)
    {
        $this->validateColumnIndex($index);
        
        $column = new DerivedColumn($this->columns[$index]->getAlias());
        
        return $column->setTable($this);
    }
public function deriveColumn ( $ index ) { $ this -> validateColumnIndex ( $ index ) ; $ column = new DerivedColumn ( $ this -> columns [ $ index ] -> getAlias ( ) ) ; return $ column -> setTable ( $ this ) ; }
Derives an expression in the query's select clause as a column of the query's associated resultset.

@param int $index
@throws \OutOfRangeException
@return multitype:\Aztech\Skwal\Expression\AliasExpression
Derives an expression in the query s select clause as a column of the query s associated resultset .