public function areNull(array $columns, $logicalAnd = true) {
        foreach ($columns as $column) {
            $this->isNull($column, $logicalAnd);
        }
        return $this;
    }
public function areNull(array $columns, $logicalAnd = true) {
        foreach ($columns as $column) {
            $this->isNull($column, $logicalAnd);
        }
        return $this;
    }
public function areNull ( array $ columns , $ logicalAnd = true ) { foreach ( $ columns as $ column ) { $ this -> isNull ( $ column , $ logicalAnd ) ; } return $ this ; }
Select a column where the values of the given columns are null
@param string $columns
@param boolean $logicalAnd Indicates whether to use logical AND (TRUE) or OR (FALSE)
@return Table
Select a column where the values of the given columns are null