[mysql] calculate support value

<?php
/*********************************
FILENAME  : psb.php
CREATE BY  : cahya dsn
PURPOSE   : calculate support value
CREATE DATE : 2012-12-31
**********************************
#table creation

USE `test`;

DROP TABLE IF EXISTS `tbl_psb`;
CREATE TABLE IF NOT EXISTS `tbl_psb` (
 `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT 'primary key untuk table tbl_psb',
 `nilai` varchar(2) NOT NULL COMMENT 'nilai',
 `jalur_masuk` varchar(4) NOT NULL COMMENT 'jalur masuk',
 `count` int(11) unsigned NOT NULL DEFAULT 0,
 PRIMARY KEY(`id`)
) ENGINE=MyISAM COMMENT='tabel untuk menyimpan data PSB';

INSERT INTO `tbl_psb`(`id`,`nilai`,`jalur_masuk`,`count`) VALUES
(NULL,'A2','PSSB',3),
(NULL,'A2','SPMB',1),
(NULL,'A3','PSSB',2),
(NULL,'A3','SPMB',3);
*/

//database configuration
$dbhost='localhost';
$dbuser='root';
$dbpass='';
$dbname='test';
//database connection
$db=new mysqli($dbhost,$dbuser,$dbpass,$dbname);
//query to get organization datas from database
$sql="SELECT nilai,jalur_masuk,count,(count/jml) AS support "
    ."FROM tbl_psb, "
    ."(SELECT nilai AS nilai2,SUM(count) AS jml "
    ."  FROM tbl_psb "
    ."  GROUP BY nilai "
    .") AS t2 "
    ."WHERE count>2 "
    ."AND nilai2=nilai";
$result=$db->query($sql);
echo "<pre>"
    ."Nilai | Jalur Masuk | Count | Support |\n";
while($records=$result->fetch_object()){
  echo  str_pad($records->nilai,6,' ',STR_PAD_BOTH)."|";
  echo  str_pad($records->jalur_masuk,13,' ',STR_PAD_BOTH)."|";
  echo  str_pad($records->count,7,' ',STR_PAD_BOTH)."|";
  echo  str_pad($records->support,9,' ',STR_PAD_BOTH)."|\n";
}
?>