public function addColumn(string $name, $value)
    {
        $this->args[] = $value;
        if (mb_strlen($this->columns) > 0) {
            $this->columns .= ", ";
        }
        $this->columns .= $name;
        if (mb_strlen($this->values) > 0) {
            $this->values .= ", ";
        }
        $argNum = count($this->args);
        $this->values .= "$".$argNum;
    }