PHP Mysql query getting total from 2 columns

I create a post just now but cannot seem to find it to add to it. Anyhow, I have 2 tables, I need to multiply qty from the one table to the mass from the other to get a total, which I have achieved with this code:

	$sql_total_mass = "
	SELECT jobs_assembly.assemble_qty, jobs.mass,
	(jobs_assembly.assemble_qty * jobs.mass) AS 'sum'	
	FROM jobs_assembly
	LEFT JOIN jobs on jobs_assembly.jobs_id =
	LEFT JOIN job_names ON jobs.job_names_id = job_names.job_id
	WHERE jobs_assembly.assemble_date = '$link_date'
	ORDER BY job_names.job_name, jobs.assembly

	$result_total_mass = mysqli_query($conn, $sql_total_mass);

	if (mysqli_num_rows($result_total_mass) > 0) {
		while($row_total_mass = mysqli_fetch_assoc($result_total_mass)) {
			echo $row_total_mass['sum'].'<br />';
		} //while
	} //if

Now I need to take all these totals and make a grand total. So basically add all the results from $row_total_mass[‘sum’] together and show it.

2 posts were merged into an existing topic: Totalling output of a query