Question

I’ve tried everything to figure this out but I can’t get the correct total. My attempts either add all the records and not just the latest ones or I only get the first record.

My first table: hubs

hubID    hubName
1           hub1
2           hub2

My second table: hub_reports

reportID    hubID          date          health         school 
1               1          2012-04-27    467            322 
2               2          2012-04-23    267            22 
3               1          2012-01-20    176            623 

So what you see is 2 tables, one with the organizations name and other info and the second with the reports that each organization submits quarterly. I want to list all the organizations and their latest report. At the bottom of the table I want to add all the available health kits and school kits that are currently available.

Here’s the code I’m using right now to display all the organizations and their latest reports.

SELECT * FROM (SELECT hubName, date, health, school FROM hub_reports,
hubs WHERE hub_reports.hubID = hubs.hubID ORDER BY date DESC) AS Total
GROUP BY hubName

This seems to work but when I try the same tactic to get the SUM of the health and school columns I don’t get the right answer.

SELECT SUM(health) FROM (SELECT hubName, date, health FROM
hub_reports, hubs WHERE hub_reports.hubID = hubs.hubID ORDER BY date
DESC) AS Total GROUP BY hubName

I tried other using a LEFT JOIN approach that I found on another forum but it didn’t seem to work any better. But I maybe I wasn’t doing it right.

Please help!

Answer 1

I just encountered a similar problem in a project of mine. A variation of this query worked for me. Hope it is helpful to you.

SELECT hubs.hubName, hub_reports.*, 
SUM(hub_reports.health) AS ttl_health, 
SUM(hub_reports.school) AS ttl_school
FROM hubs, hub_reports 
WHERE hub_reports.hubID = hubs.hubID 
GROUP BY hub_reports.hubID
ORDER BY hub_reports.date DESC

Here’s the PHP:

$rs = mysql_query( 'SELECT hubs.hubName, hub_reports.*, 
    SUM(hub_reports.health) AS ttl_health, 
    SUM(hub_reports.school) AS ttl_school
    FROM hubs, hub_reports 
    WHERE hub_reports.hubID = hubs.hubID 
    GROUP BY hub_reports.hubID
    ORDER BY hub_reports.date DESC' );

$grand_total['school']=0;
$grand_total['health']=0;

while ( $row = mysql_fetch_assoc( $rs ) ){ // Step through each hub
    echo "{$row['hubName']} shows {$row['ttl_school']} total school, {$row['ttl_health']} total health";
    $grand_total['school'] += $row['ttl_school'];
    $grand_total['health'] += $row['ttl_health'];
}

echo "Grand Total School: {$grand_total['school']}, Grand Total Health: {$grand_total['health']}";