[RESOLVED] PHP -> MySQL Simple while loop issue

jammert1001

Hi eveyrone,

First off, I promise this is not any type of homework assignment, even though this probably looks really simple. We are running PHP 5.1 and MySQL 4.1.

I am attempting to create a site survey for one of our student development programs. I'm trying to make a result.php file which will take the SUM of the kids who took the survey (they are asked to fill in what grade they are in.)

I'm trying to create a while loop which will go through each grade, rather than creating a new query command per grade. What is happening is that when I execute the php file, I don't receive any error, even from mysql_error().

<?php
$dbhost = 'myserver';
$dbuser = 'myusername';
$dbpass = 'usernamepw';

$conn = mysql_connect($dbhost,$dbuser,$dbpass) or die ('Error connecting to mysql');
$dbname = 'surveys';
$i = 9;
// Declare variable results...
$query9 = "SELECT SUM(grade9) FROM surveys.cte_survey";
$queryg10 = "SELECT SUM(grade10) FROM surveys.cte_survey";
$queryg11 = "SELECT SUM(grade11) FROM surveys.cte_survey";
$queryg12 = "SELECT SUM(grade12) FROM surveys.cte_survey";
while ($i<=12)
{
$grade$i = mysql_query($query$i) or die (mysql_error());
printf("%u ",$grade$i);
$i++;
}
mysql_close($conn);
?>

Now if I change my while loop to use "$grade9" in to replace my "$grade$i" statement, then I receive the results "2 3 4 5". It's like it just counts how many times the $i loop executed, but not the amount of students who have taken the survey.

I've tried changing things in the while loop to "$grade[$i]", "$grade['$i']" "$grade$i" all without success. I have no other idea how I can approach this and I'm hoping others may have some insight.

Here is the data in my "grade9,grade10,grade11,grade12" columns located in my surveys.cte_survey.

mysql> SELECT SUM(grade9),SUM(grade10),SUM(grade11),SUM(grade12) from surveys.cte_survey;
+-------------+--------------+--------------+--------------+
| SUM(grade9) | SUM(grade10) | SUM(grade11) | SUM(grade12) |
+-------------+--------------+--------------+--------------+
| 3 | 3 | 2 | 1 |
+-------------+--------------+--------------+--------------+
1 row in set (0.00 sec)

If anyone can point me in the right direction, I would really appreciate it. Thank you for your time,

-MT

laserlight

You probably want to do something like this:

for ($i = 9; $i <= 12; ++$i)
{
    $query = "SELECT SUM(grade$i) FROM surveys.cte_survey";
    $result = mysql_query($query) or die(mysql_error());
    printf("&#37;u ", mysql_result($result, 0));
}

That said, if it is not too late to change, I note that your database design is probably a bad one. Typically, instead of numbered columns, you really want a new table (in this case, probably a grades table).

jammert1001

Thank you for your quick response! I apologize for my original post being in the incorrect section.

That did work. I appreciate your suggestion; Unfortunatley, I'm only working with what I am given... and I'm not given too much... ack... Thank you very much for your help!