Win,

SQL Injection can definately be a thorn in your side. However, most of these problems are eliminated when you use DBI's bind method. 
#assuming you're connected, with a $dbh
#my $sql = "select ? from ?"; #incorrect, thanks wfsp
my $sql = "select ? from myTable";
my $sth=$dbh->prepare( $sql ) ;
$sth->bind_param(1, $col_to_select );
#$sth->bind_param(2, $table ) ; #also incorrect
$sth->execute ;

[download]
DBI does a good job of escaping and db-quoting the things you bind this way. Then you can relax. If you use andye's method for filtering the input and paring away only things you -do- want via your favorite untaint method, you can relax even harder.

Peace, monks.

Update: wfsp has pointed out that table names shouldn't be bound with bind_params. Turns out he's absolutely correct. It's all documented in perldoc DBI. I've also fixed the code and commented out the garbage. Thanks wfsp.
Bro. Doug :wq

In reply to Re: Preventing injection attacks by Bro. Doug
in thread Preventing injection attacks by Win

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.