Instead of relying on user input for the values of the params 'order_by' and 'order_by_check', you should use a lookup table instead. Consider this: the user enters in their own values instead of using the buttons you supply: 
bar.cgi?order_by=foo&order_by_check=bar
Now what? You get a database error. A lookup table is a hash that contains valid keys, the values can be any true value, : 
my %lookup = (
   FAULT_NO => 'FAULT_NO',
   ISSUE    => 'ISSUE',
   RESPONSE => 'RESPONSE',
);
# task of automating the creation of the hash
# is left as an excerise to the reader ;)

[download]
Now, instead of just accepting the parameter as is from CGI.pm, you can 'filter' it: 
$order_by       = $lookup{ param('order_by') };
$order_by_check = $lookup{ param('order_by_check') };

if ($order_by) {
   ...
}
...

[download]
When the user enters a value for a field that doesn't exist, the error is treated the same as if the user did not enter any value for a field at all. Works like a charm ... until you want to inform the user of that fact. :(

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

In reply to (jeffa) 3Re: Using CGI params for SQL statement by jeffa
in thread Using CGI params for SQL statement by maderman

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.