eval {
    $sth->execute();
    ...
};
if ( $@ ) {
    # log the full error message
    write_log( $sth->errstr );

    # and re-throw the common message
    die 'HEY!!!! Something is messed up here!';
}

##</code><code>##

my $sql = q{INSERT INTO mytable VALUES ( ?,?,? )};
eval {
    $dbh->do( $sql, undef, ($val1, $val2, $val3) );
};
if ( $@ ) }
    # error trapping here
    ...
}