Question

I have an array which each one of them have a different sum on database (maybe some of them are empty or there is no record for them)

i need to know which one has bigger sum THAN ALL THE OTHERS (ON MY ARRAY) and put that one in $bigger variable, ($bigger = $value)

My try:

$new = 0;
$myarray = array('2', '5', '17', '55');

foreach($myarray as $value) {
    $before = intval($new);

    $query = mysql_query("SELECT SUM(total) AS totals FROM table WHERE id='$value'");
    $result = mysql_fetch_assoc($query);
    $new = intval($result['totals']);

    if ($new > $before){
        $biggest=intval($value);
    }
}

but it only shows if the newer one has bigger value than the older one, not bigger than all of them

Any help is appreciated

Answer 1

I would eliminate the looping altogether and do it like this:

$myarray = array('2', '5', '17', '55');
$query = "SELECT SUM(total) AS totals FROM table WHERE id IN (" . implode(', ', $myarray) . ") GROUP BY id ORDER BY totals DESC LIMIT 1";
$result = mysql_query($query);
$row = mysql_fetch_assoc($result);

Note that is you want to receive data for all id’s in sorted order you can simply remove the LIMIT clause, and add a looping to read out each row of the result set.

I would also recommend not using the mysql_* functions as they are deprecated. If you are just learning PHP, you should learn using mysqli_* functions, PDO or something that will enjoy support in the future.

You should also learn how to test for failure conditions on your database queries. My example is a simple one, but production code should test the success/failure of the query and of the fetch operation.