DBI-trace() might be what you are looking for.
See also:

• http://search.cpan.org/~timb/DBI-1.630/DBI.pm#TRACING
  
• http://oreilly.com/catalog/perldbi/chapter/ch04.html - search for "Tracing DBI Execution "
• http://www.felixgers.de/teaching/perl/perl_DBI.html - see the debugging section

Update: The following perlmonks thread might also be of interest to you: Pretty printing the exact query (with bind variables) executed by DBI?
It seems the parameters are actually never really inserted into the statement, but passed separately to the DBD. So if you really want the statement with the parameters inserted, you will have to do it manually (see also the solutions by awohld and hdb in this thread).