ขอความช่วยเหลือบรรดาเซียนๆ การ inner join หลายๆตารางหน่อยคับ มีเรื่องให้ช่วย ค่อนข้างซับซ้อนสำหรับผม

 <?
			  $sql="select * from ref_position where position_id between '01' and '04' order by position_id DESC";
			  $qq=mysql_query($sql,$condb);
			  $sums=0;$sum=0;$spa=0;
			  while($row=mysql_fetch_array($qq))
			  {		$au=0;$bc=0;$pb=0;$ms=0;$pba=0;$dhp=0;$ch=0;$pa=0;
			  		$sql="select citizen_id,stf_fname,stf_lname from staff where  substafftype_id='1' and position_id='$row[0]' ";
					$qqo=mysql_query($sql,$condb);
					while($row1=mysql_fetch_array($qqo))
			  		{
							$sql="select max(grad_lev_id) from seducation where citizen_id='$row1[0]'";
							$qqs=mysql_query($sql,$condb);
							$rows=mysql_fetch_array($qqs);
							if($rows[0]=='80'){$dhp++;}if($rows[0]=='70'){$pba++;}if($rows[0]=='60'){$ms++;}
							if($rows[0]=='50'){$pb++;}if($rows[0]=='40'){$bc++;}if($rows[0]=='35'){$au++;}
							if($rows[0]=='30'){$pa++;}if($rows[0]=='00'){$ch++;}
							
							mysql_free_result($qqs);
					}mysql_free_result($qqo);			
				$sum=$au+$bc+$pb+$ms+$pba+$dhp+$ch+$pa;
				$spa=$spa+$pa;$sch=$sch+$ch;$sau=$sau+$au;
				$sbc=$sbc+$bc;$spb=$spb+$pb;$sms=$sms+$ms;
				$spba=$spba+$pba;$sdhp=$sdhp+$dhp;
				$sums=$sums+$sum;
			  ?>