...
my $dbh_in = test->connect_mysql(); 
my $sth_in = $dbh_in->prepare("insert into my_table(name_1,name_2,name_3,name_4) 
values(?, ?, ?, ?) where user='$user'")"                                             or &die("Can't add data, please try again later! ",$dbh_in->errmsg); 
foreach my $name (@names) { #got this array from the form
  my @fields = $name;
$sth->execute(@fields);
}
$dbh_in->disconnect();