sub makeSql {
  my @xpid = shift; # <----------- error
  my $return;       # try: my $xpid = shift
  my $i = 0;                  ^
  foreach my $item (@xpid) { # <-- error
    $return .= $xpid[$i];    # <-- error

# try: foreach my $item (@$xpid)
                         ^
# try: $return .= $$xpid[$i];
                  ^