Perl和参数化语句

我正在寻找参数化语句没有被正确执行的确认。当前代码如下：

$ywant = "user supplied integer";
$select = "SELECT a.Authors, a.PublicationYear, a.Title, a.URL, a.ArticleID, f.Format ".
          "FROM   tbl_ETI_Article a, tbl_ETI_Format f  ".
          "WHERE  a.PublicationYear = '".$ywant."' ".
          "AND a.FID = f.FID ".
          "ORDER BY a.PublicationYear DESC, a.Title ASC";

$sth = $dbh->prepare( " $select " );
$sth->execute();

我知道选择字符串中的 $ywant 变量应该替换为占位符 '?' 然后将用户提供的数据作为参数放置在执行语句中。

我的问题是上述内容是否仍然提供任何针对注入攻击的保护，因为它仍在“准备中”？

回答

$ywant = "user supplied integer";
$select = qq{SELECT a.Authors, a.PublicationYear, a.Title, a.URL, a.ArticleID, f.Format
FROM   tbl_ETI_Article a, tbl_ETI_Format f
WHERE  a.PublicationYear = ?
AND a.FID = f.FID
ORDER BY a.PublicationYear DESC, a.Title ASC};

$sth = $dbh->prepare($select);
$sth->execute($ywant);