If an error did occur (maybe you don't have write permission for the current directory) most likely you will see the error message twice - once generated by the DBI/DBD code, and once from the die $@;

That can easily be prevented by doing:

  $dbh->{PrintError} = 0;
[download]

The DBI manual recommends this:

If you turn "RaiseError" on then you'd normally turn "PrintError" off.
[download]

my $entries =
    eval {
        my $entries = 0;
        my $sth = $dbh->prepare ($sql); #2

        while (my ($name, $age) = each %people) { #3
            ++$entries if $sth->execute ($name, $age); #4
        }

        $dbh->commit (); #5
        return $entries;
    } or do {
        my $err = $@;

        eval {$dbh->rollback ()} or $err .= "\n   Rollback processing 
+failed!";
        die $err;
    };
[download]

That code will die if %people is empty. I'd write that as:

my $entries;
eval {
    ... stuff ...
    $entries++ if $sth->execute($name, $age);
    ... more stuff ...
    $dbh->commit;
    1;
} or do {
    ... rollback and die ...
};
[download]