use strict;
use warnings;
use DBI;
use CGI;

my $dbh = DBI->connect("DBI:mysql:database=mygb;host=localhost;port=3306", "mygbuser", "mygbpw");
my $cgi = CGI->new;

print $cgi->header;
print $cgi->start_html(-title => 'MyGuestbook');
print $cgi->h1('MyGuestbook / Alle Eintraege');

my $sth = $dbh->prepare("SELECT email, username, message FROM entries");
$sth->execute;

while(my $row = $sth->fetchrow_hashref) {
   print $cgi->ul({class => 'entrylist'}
      $cgi->li(
         $cgi->h1($cgi->a({href => $row->{'email'}}, $row->{'username'})),
         $cgi->div($row->{'message'})
      )
   );
}

print $cgi->end_html;

use strict;
use warnings;
use DBI;
use CGI;

my $dbh = DBI->connect("DBI:mysql:database=mygb;host=localhost;port=3306", "mygbuser", "mygbpw");
my $cgi = CGI->new;

print $cgi->header;
print $cgi->start_html(-title => 'MyGuestbook');
print $cgi->h1('MyGuestbook / Ein Eintraeg');

my $eintrag = $cgi->param("entry");
my $sth = $dbh->prepare("SELECT email, username, message FROM entries WHERE entry_id=?");
$sth->bind_param(1, $eintrag);
$sth->execute;

my $eintrag = $sth->fetchrow_hashref;

print $cgi->ul({class => 'entrylist'}
   $cgi->li(
      $cgi->h1($cgi->a({href => $eintrag->{'email'}}, $eintrag->{'username'})),
      $cgi->div($eintrag->{'message'})
   )
);

print $cgi->end_html;