...so I embed the query into a "NEXT" link...

Am I understanding correctly that if I were to view-source on your page I would see within the NEXT link the SQL code that will be passed to the database? If that's the case, someone with a little motivation could construct a query that passes any SQL he wants back to the server. ...find out what tables exist, look up user account information, drop tables, and make a big mess.

POST isn't the answer either. The answer is to treat any data that comes from the client like it's capable of transmitting ebola. And because your URL has a .pl in it, the headline will read "Hackers attack insecure Perl script".