public function getColumns(): array
    {
        $tSelects = isset($this->statements['selects']) === true ? $this->statements['selects'] : [];
        $tColumns = [];
        foreach ($tSelects as $key => $value) {
            if (\is_string($value)) {
                if (\is_int($key)) {
                    $tElements = explode('.', $value);
                    if (!\in_array('*', $tElements, true)) {
                        $tColumns[$tElements[1] ?? $tElements[0]] = $value;
                    }
                } elseif (\is_string($key)) {
                    $tColumns[$value] = $key;
                }
            }
        }
        return $tColumns;
    }