PHP variable additions - php

Question

Hey does anyone know a reason why this is not working? its not calculating any of the additions and just entering 0 into the database. Any help would be great, thank you!.
$member_id = //users member id in database//
$track = //the track results being updated//
$engine = //the engine id from the members table in database//
$engine_points_system = array();
$engine_points_system["qualpos1"] = 30;
$engine_points_system["qualpos2"] = 20;
$engine_points_system["qualpos3"] = 18;
$engine_points_system["qualpos4"] = 17;
$engine_points_system["qualpos5"] = 16;
$enginepoints = 0;
$qualifyingpoints = 0;
$results_query = mysql_query("SELECT pos_1, pos_2, pos_3, pos_4, pos_5
from engine_qualifying_results WHERE track_id = '$track'")
or die ("Failed to update" . mysql_error());
$row = mysql_fetch_array($results_query);
$enginequalifying = array();
for ($i = 1; $i <= 5; $i++) {
$enginequalifying["pos$i"] = $row['pos_$i'];
}
for($i = 1; $i <=5; $i++) {
if($engine == $enginequalifying["pos$i"]){
$enginepoints += $engine_points_system["qualpos$i"];
$qualifyingpoints += $engine_points_system["qualpos$i"];
}
}
$results_query = mysql_query("INSERT INTO member_results (member_id, engine_points)
VALUES ('$member_id', $enginepoints')")
or die ("Failed to update" . mysql_error());

Answer 1

$enginequalifying["pos$i"] = $row['pos_$i'];
In this line you have 'pos_$i'. This is the literal string 'pos_$i'. You should use "pos_$i" instead.
$enginequalifying["pos$i"] = $row["pos_$i"];
UPDATE:
In your code $enginequalifying is redundant, and not needed. You can just use $row in its place.
for($i = 1; $i <=5; $i++){
if($engine == $row["pos_$i"]){
$enginepoints += $engine_points_system["qualpos$i"];
$qualifyingpoints += $engine_points_system["qualpos$i"];
}
}
Also, as #ax. points out, you have an extra ' (or a missing ') in your INSERT.
$results_query = mysql_query("INSERT INTO member_results (member_id, engine_points)
VALUES ('$member_id', '$enginepoints')")
or die ("Failed to update" . mysql_error());

Answer 2

Look at this code:
<?php
$i = 5;
print "i is $i";
print "\n";
print 'i is $i';
?>
You'd expect it to print:
i is 5
i is 5
But instead, it will print:
i is 5
i is $i
This happens because when the string is wrapped in single quotes, $i is not evaluated. It is just the string $i.
To fix the code, try replacing this line:
$enginequalifying["pos$i"] = $row['pos_$i'];
With this line:
$enginequalifying["pos$i"] = $row["pos_$i"];
Quotes make a difference.
And by the way, ESCAPE YOUR SQL!!!. Please?

Answer 3

Not an answer, but too ugly to put into a comment: You could bypass the entire loop to build the enginequalifying array by simply doing:
SELECT pos_1 AS pos1, pos_2 AS pos2, etc...
for your query, then simply having:
$enginequalifying = mysql_fetch_assoc($result);
It's a waste of CPU cycles to have PHP fetch/rename database fields for you when a simple as alias in the original query string can accomplish the exact same thing.
And incidentally, this will also remove the string-quoting error you've got that Rocket pointed out in his answer.

Answer 4

I dont think it is possible to say without knowing what you have in your database.
But I can tell you that you have a syntax error in the last SQL query ($enginepoints ends with a quote).