Simple PHP Array Issue with Key Comparison

Question

I've been pulling my hair out on this one all afternoon. Basically, I have a long table of values (stored in SQL) and I want to go through the entire table and count the number of times each value shows up. I've called the values "pid" integers.

The best way I thought of to do this was to create an array with the PIDs as the key of the array, and the number of times each PID has occured in the table as the value at that key. Then go through the entire list and either add the PID to the array if it didn't already exist, or increment the click value if it already exists. The goal is to then figure out which PID has the highest number of clicks.

It sounds straightforward, and it is! I think I must have an error in my syntax somewhere because everything seems right. This is my first time working with arrays in PHP so be nice :)

Thanks so much!

$tabulation = array();

while ($row = mysql_fetch_array($result)) {
    $pid = $row[1];  

    //if this post isn't in the tabulation array, add it w a click value of 1
    if ( !isset( $tabulation[$pid] ) ){ array_push( $tabulation[$pid], 1 ); }
    //if this post is already in the tabulation array, incrment its click value by 1
    else { 
        $t = $tabulation[$pid]; $t++; $tabulation[$pid] = $t;
    }
}

$highestClicksValue = -1;
$highestClicksPID = -1;
foreach ($tabulation as $pid => $clicks){
    if ($clicks > $highestClicksValue){ $highestClicksPID = $pid; }
    printf("PID: ". $tabulation[$pid] . " clicks: " . $tabulation[$clicks] . "<br />");
}

Answer 1

I know you're looking for a PHP answer, but have you considered that this is what SQL is best at?

select pid,count(*)
  from theTable
 group by pid
 order by count(*) desc

Just a thought...

Answer 2

Why are you using the array key and value as keys for $tabulation in the last foreach? This should work...

$tabulation = array();

while ($row = mysql_fetch_array($result)) {
    $pid = $row[1];  

    //if this post isn't in the tabulation array, add it w a click value of 1
    if ( ! isset( $tabulation[$pid] ))
      $tabulation[$pid] = 1;
    //if this post is already in the tabulation array, incrment its click value by 1
    else
      $tabulation[$pid]++;
}

arsort($tabulation);
$highestClicksValue = reset($tabulation);
$highestClicksPID = key($tabulation);
foreach ($tabulation as $pid => $clicks){
    print("PID: ". $pid . " clicks: " . $clicks . "<br />");
}