The DB console application may be running with a different encoding than your Perl application, and/or it may be telling the DB explicitly what encoding it is using.

I would suggest (1)setting your HTML form's enctype explicitly, and (2)learning how to tell your DB that you are speaking a specific encoding. The latter might be a SQL statement, an option to your DBI->connect, or possibly some combination of the two.

It would help, a little, to know which DBD you're using.