I use the php operator && to select multiple data so that there is no duplication on mysql. Does the code that I use below run fine? Is there a more simple use of PHP operators?
$date= date('Y/m/d');
$cekcount = mysql_num_rows(mysql_query("SELECT * FROM `pending_media` where `mediaid`='$dielz'"));
$cekcount2 = mysql_num_rows(mysql_query("SELECT * FROM `media` where `mediaid`='$dielz'"));
$selectcount = mysql_query("SELECT * FROM `media` where `date`='$date' AND `uplink`='$nam'");
$cekcount3 = mysql_num_rows($selectcount);
if($cekcount == 0 && $cekcount2 == 0 && $cekcount3 == 0){
mysql_query("INSERT INTO pending_media VALUES('','$nam','$dielz')");
Upgrade to mysqli, I'll recommend object-oriented syntax because it is nicer to work with.
In accordance with the best practice of "minimize calls to the database", I'll condense your three queries into a single, united SELECT call then check for a non-0 result.
My untested suggestion using mysqli's object-oriented syntax (I did test the SELECT query in PHPMyAdmin):