รบกวนเรื่องการ Query ข้อมูลออกมาช้า จะหาวิธีตรวจสอบแบบไหนกับการ OrderBy GroupBy ของข้อมูลครับ

			if($_POST['Customer']!=""){
					$c_name=$_POST['Customer']; //file name output
					$Customer="where job.customer_name='".$_POST['Customer']."' ";
						
					if($_POST['project_code']!=""){
							//echo	$p_code=$_POST['project_code']; //file name output
							$project_code="and job.project_code='".$_POST['project_code']."' ";	
					}
					else{
							$p_code="All";
							$project_code="";
					}
			}else{
					$c_name="All";
					$Customer="";
			}
			if(@$_POST['job_no']!=""){
				if($Customer=="")
					$job_no="where job.job_no LIKE '%".trim($_POST['job_no'])."%' ";
				else
					$job_no="and job.job_no LIKE '%".trim($_POST['job_no'])."%' ";
			}else{
				$job_no="";
			}
			
			if(isset($_POST['job_status'])){
				$sub_bill="LEFT JOIN sub_bill on sub_bill.job_no=job.job_no ";
				if(@$_POST['job_status']!=""){
					if($Customer=="" && $job_no=="")
						$job_status="where sub_bill.job_status='".$_POST['job_status']."' ";
					else
						$job_status="and sub_bill.job_status='".$_POST['job_status']."' ";
				}else{
					$job_status="";
				}
			}
			
			if(isset($_POST['billing_status'])){
				$payment="LEFT JOIN payment on payment.job_no=job.job_no ";
				if(@$_POST['billing_status']!=""){
					if($Customer=="" && $job_no=="" && $job_status=="")
						$billing_status="where payment.billing_status='".$_POST['billing_status']."' ";
					else
						$billing_status="and payment.billing_status='".$_POST['billing_status']."' ";
				}else{
					$billing_status="";
				}
			}
			
			if(@$_POST['date_start']!="" && $_POST['date_end']!=""){
				if($Customer=="" && $job_no=="" && $job_status=="" && $billing_status=="")
					$date_se="where job.date_create between '".$_POST['date_start']."' and '".$_POST['date_end']."' ";
				else
					$date_se="and job.date_create between '".$_POST['date_start']."' and '".$_POST['date_end']."' ";
			}else{
				$date_se="";
			}
		
	$query_pag_data= "SELECT job.job_no,job.job_ref, job.branch_name ,sub_bill.payment_status, payment.billing_status,payment.job_item FROM job ";
	$query_pag_data.= "$sub_bill $payment "; // LEFT JOIN Table
	$query_pag_data.= "$Customer $project_code $job_no $job_status $billing_status $date_se "; // Condition
	//$query_pag_data.= "GROUP BY job.job_ref,job.job_no DESC ";
	$query_pag_data.= "GROUP BY job.job_ref, job.job_no DESC ";
	$query_pag_data.= "LIMIT $start, $per_page ";
	$result_pag_data = mysql_query($query_pag_data) or die('MySql Error' . mysql_error());
	$num_rows=mysql_num_rows($result_pag_data);
	$height=$num_rows*30;
	$start+=1;

	$query_pag_data= "SELECT job.job_no,job.job_ref, job.branch_name ,sub_bill.payment_status, payment.billing_status,payment.job_item FROM job ";
	$query_pag_data.= "$sub_bill $payment "; // LEFT JOIN Table
	$query_pag_data.= "$Customer $project_code $job_no $job_status $billing_status $date_se "; // Condition

SELECT job.job_no,job.job_ref, job.branch_name ,sub_bill.payment_status, payment.billing_status,payment.job_item 
FROM job 
LEFT JOIN sub_bill on sub_bill.job_no=job.job_no 
LEFT JOIN payment on payment.job_no=job.job_no 
GROUP BY job.job_ref, job.job_no DESC LIMIT 0, 25

SELECT j.job_no,j.job_ref, j.branch_name, b.payment_status, p.billing_status, p.job_item 
FROM job j, sub_bill b, payment p
WHERE b.job_no=j.job_no and p.job_no=j.job_no 
GROUP BY j.job_ref, j.job_no
ORDER BY j.job_ref, j.job_no DESC 
LIMIT 0, 25

SELECT j.job_no,j.job_ref, j.branch_name, b.payment_status, p.billing_status, p.job_item 
FROM job j
INNER JOIN sub_bill b ON b.job_no=j.job_no
LEFT JOIN payment_status p on p.job_no=j.job_no 
GROUP BY t.job_ref, t.job_no
ORDER BY t.job_ref, t.job_no DESC