...
RaiseError  => 1,
HandleError => Exception::Class::DBI->handler,
...

##</code><code>##

eval {
  # if I fail, I will let you know
  $dbh->do("evil query"); 
};

my $ex = undef;

if ( $ex = Exception::Class::DBI->caught() ) {
   # log error in $ex->errstr
   # show users a general error screen
}