protected function buildCompleteString($format)
    {
        $placeholderValues = [
            '{type}' => $this->type,
            '{length}' => $this->buildLengthString(),
            '{unsigned}' => $this->buildUnsignedString(),
            '{notnull}' => $this->buildNotNullString(),
            '{unique}' => $this->buildUniqueString(),
            '{default}' => $this->buildDefaultString(),
            '{check}' => $this->buildCheckString(),
            '{comment}' => $this->buildCommentString(),
            '{pos}' => $this->isFirst ? $this->buildFirstString() : $this->buildAfterString(),
            '{append}' => $this->buildAppendString(),
        ];
        return strtr($format, $placeholderValues);
    }