Exhausting Memory - Tried Fixing Loops, Still Does Not Work - php

Question

I'm currently experiencing a memory usage issue - but I cannot figure out where. I've tried replacing some of my foreach loops with for loops or by issuing another query to the DB, but I am still gettting the same error - "Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 72 bytes) in on line 109". Can anyone provide some insight as to what may be causing the issue? Thank you!
Code after #Patrick 's answer:
$participating_swimmers = array();
$event_standings = array();
$qualifying_times = array();
$events = array();
$current_event = '';
$select_times_sql = "SELECT event, time, name, year, team, time_standard, date_swum
FROM demo_times_table
WHERE sex = 'M' AND (time_standard = 'A' OR time_standard = 'B')
ORDER BY event, time ASC";
$select_times_query = mysql_query($select_times_sql);
//Create array with the current line's swimmer's info
while ($swimmer_info = mysql_fetch_assoc($select_times_query)) {
if($current_event != $swimmer_info['event']){
$events[] = $current_event = $swimmer_info['event'];
}
//Create array with the current line's swimmer's info
$swimmer_info["time"] = $select_times_row['time'];
$swimmer_info["name"] = $select_times_row['name'];
$swimmer_info["year"] = $select_times_row['year'];
$swimmer_info["team"] = $select_times_row['team'];
$swimmer_info["time_standard"] = $select_times_row['time_standard'];
$swimmer_info["date_swum"] = $select_times_row['date_swum'];
//Create "Top 8" list - if more than 8 A cuts, take them all
if (($swimmer_info["time_standard"] == "A") || ($swimmer_info["time_standard"] == "B")) {
//Check if there are 8 or less entries in the current event, or if the swim is an A cut
if ((count($event_standings[$current_event]) < 8) || ($swimmer_info["time_standard"] == "A")) {
//Add swimmer to the list of invites
$event_standings[$current_event][] = $swimmer_info;
//Keep only the identifying information about the swimmer
$condensed_swimmer_info["name"] = $swimmer_info["name"];
$condensed_swimmer_info["year"] = $swimmer_info["year"];
$condensed_swimmer_info["team"] = $swimmer_info["team"];
//Check if swimmers name already appears in list
if (!in_array($condensed_swimmer_info, $participating_swimmers)) {
//It is a unique user - add them to the list
$participating_swimmers[] = $condensed_swimmer_info;
}
} else {
//Add the qualifying time that did not fit into the list to a list of qualifying times
$qualifying_times[$current_event][] = $swimmer_info;
}
}
}
//Sort each array of times in descending order
arsort($event_standings);
arsort($qualifying_times);
$num_of_swimmers = count($participating_swimmers);
while ($num_of_swimmers < 80) {
foreach ($events as $loe) {
$num_of_qualifying_times = count($qualifying_times[$loe]);
$swimmer_info = $qualifying_times[$loe][$num_of_qualifying_times-1];
$event_standings[$loe][] = $swimmer_info;
//Keep only the identifying information about the swimmer
$condensed_swimmer_info["name"] = $swimmer_info["name"];
$condensed_swimmer_info["year"] = $swimmer_info["year"];
$condensed_swimmer_info["team"] = $swimmer_info["team"];
//Check if swimmers name already appears in list
if (!in_array($condensed_swimmer_info, $participating_swimmers)) {
//It is a unique user - add them to the list
$participating_swimmers[] = $condensed_swimmer_info;
}
//Remove time from array of qualifying times
unset($qualifying_times[$loe][$num_of_qualifying_times-1]);
}
$new_num_of_swimmers = count($participating_swimmers);
if($num_of_swimmers == $new_num_of_swimmers) break;
else $num_of_swimmers = $new_num_of_swimmers;
}
arsort($event_standings);
arsort($qualifying_times);
foreach($event_standings as $loe => $event_swimmer) {
echo "<h1>",$loe,"</h1><br />";
foreach ($event_swimmer as $es) {
echo $es["time"]," ",$es["name"]," ",$es["team"],"<br />";
}
}

Answer 1

Large data in database is the problem 95% !
- try using limit x,y in your queries , and put those queries in some loop .
- see http://php.net/manual/en/function.mysql-free-result.php it might help
<?php
$participating_swimmers = array();
$event_standings = array();
$qualifying_times = array();
$select_times_sql = "SELECT *
FROM demo_times_table
WHERE sex = 'M'
ORDER BY time ASC";
$select_times_query = mysql_query($select_times_sql);
while ($select_times_row = mysql_fetch_assoc($select_times_query)) {
//Create array with the current line's swimmer's info
$swimmer_info["time"] = $select_times_row['time'];
$swimmer_info["name"] = $select_times_row['name'];
$swimmer_info["year"] = $select_times_row['year'];
$swimmer_info["team"] = $select_times_row['team'];
$swimmer_info["time_standard"] = $select_times_row['time_standard'];
$swimmer_info["date_swum"] = $select_times_row['date_swum'];
//Create "Top 8" list - if more than 8 A cuts, take them all
if (($swimmer_info["time_standard"] == "A") || ($swimmer_info["time_standard"] == "B")) {
//Check if there are 8 or less entries in the current event, or if the swim is an A cut
if ((count($event_standings[$current_event]) < 8) || ($swimmer_info["time_standard"] == "A")) {
//Add swimmer to the list of invites
$event_standings[$current_event][] = $swimmer_info;
//Keep only the identifying information about the swimmer
$condensed_swimmer_info["name"] = $swimmer_info["name"];
$condensed_swimmer_info["year"] = $swimmer_info["year"];
$condensed_swimmer_info["team"] = $swimmer_info["team"];
//Check if swimmers name already appears in list
if (!in_array($condensed_swimmer_info, $participating_swimmers)) {
//It is a unique user - add them to the list
$participating_swimmers[] = $condensed_swimmer_info;
}
} else {
//Add the qualifying time that did not fit into the list to a list of qualifying times
$qualifying_times[$current_event][] = $swimmer_info;
}
}
}
mysql_free_result($select_times_query);
//Sort each array of times in descending order
arsort($event_standings);
arsort($qualifying_times);
$num_of_swimmers = count($participating_swimmers);
$sql = "SELECT DISTINCT(event)
FROM demo_times_table
WHERE sex = 'M' limit 80";
$query = mysql_query($sql);
while ($row = mysql_fetch_assoc($query)) {
$loe = $row['event'];
$num_of_qualifying_times = count($qualifying_times[$loe]);
$event_standings[$loe][] = $qualifying_times[$loe][$num_of_qualifying_times-1];
//Keep only the identifying information about the swimmer
$condensed_swimmer_info["name"] = $qualifying_times[$loe][$num_of_qualifying_times]["name"];
$condensed_swimmer_info["year"] = $qualifying_times[$loe][$num_of_qualifying_times]["year"];
$condensed_swimmer_info["team"] = $qualifying_times[$loe][$num_of_qualifying_times]["team"];
//Check if swimmers name already appears in list
if (!in_array($condensed_swimmer_info, $participating_swimmers)) {
//It is a unique user - add them to the list
$participating_swimmers[] = $condensed_swimmer_info;
}
//Remove time from array of qualifying times
unset($qualifying_times[$loe][$num_of_qualifying_times-1]);
}
$num_of_swimmers = count($participating_swimmers);
mysql_free_result($query);
arsort($event_standings);
arsort($qualifying_times);
$sql = "SELECT DISTINCT(event)
FROM demo_times_table
WHERE sex = 'M'";
$query = mysql_query($sql);
while ($row = mysql_fetch_assoc($query)) {
$loe = $row['event'];
echo "<h1>".$loe."</h1><br />";
foreach ($event_standings[$loe] as $es) {
echo $es["time"]." ".$es["name"]." ".$es["team"]."<br />";
}
}
/*
foreach ($participating_swimmers as $ps) {
echo $ps["name"]."<br /><br />";
}
echo "<br /><br />";
*/
?>

Answer 2

Instead of doing a query within a query, with the potential for logic holes that create a never-ending loop, you can condense it into a single query. For your first block, both loops are just checking for the current event and the sex of the participant, right? So:
$result = SELECT * FROM <my database> WHERE sex = 'M' ORDER BY time ASC
Then you can pull whichever rows you want during the while ($row = mysql_fetch_assoc($result)) loop and compensate for non-distinct values in another way.
One other source of the never-ending loop could be in the block where you sort the qualifying times. You're using "unset" after each, which could be getting the pointer stuck. You could try adding array_values($qualifying_times) after the unset to reindex the array.

Answer 3

Frist off, lose the SELECT DISTINCT like so:
$events = array()
$current_event = '';
$select_times_sql = "SELECT event, time, name, year, team, time_standard, date_swum
FROM demo_times_table
WHERE sex = 'M' AND (time_standard = 'A' OR time_standard = 'B')
ORDER BY event, time ASC";
$select_times_query = mysql_query($select_times_sql);
//Create array with the current line's swimmer's info
while ($swimmer_info = mysql_fetch_assoc($select_times_query)) {
if($current_event != swimmer_info['event']){
$events[] = $current_event = $swimmer_info['event'];
}
//Create "Top 8" list - if more than 8 A cuts, take them all
//Check if there are 8 or less entries in the current event, or if the swim is an A cut
This also loses a bit of redundant code, and can speed up the final output (note the commas in the echo statements - the string doesn't need to be concatenated before it is spat out)
foreach($event_standings as $loe => $event_swimmer) {
echo "<h1>",$loe,"</h1><br />";
foreach ($event_swimmer as $es) {
echo $es["time"]," ",$es["name"]," ",$es["team"],"<br />";
}
}
The final problem lies in the second while loop, where the info being put into $condensed_swimmer_info doesn't have the -1 in place, thus is always blank, and $num_of_swimmers never rises to more than 1 over its original value:
while ($num_of_swimmers < 80) {
foreach ($events as $loe) {
$loe = $row['event'];
$num_of_qualifying_times = count($qualifying_times[$loe]);
$swimmer_info = $qualifying_times[$loe][$num_of_qualifying_times-1];
$event_standings[$loe][] = $swimmer_info;
//Keep only the identifying information about the swimmer
$condensed_swimmer_info["name"] = $swimmer_info["name"];
$condensed_swimmer_info["year"] = $swimmer_info["year"];
$condensed_swimmer_info["team"] = $swimmer_info["team"];
//Check if swimmers name already appears in list
if (!in_array($condensed_swimmer_info, $participating_swimmers)) {
//It is a unique user - add them to the list
$participating_swimmers[] = $condensed_swimmer_info;
}
//Remove time from array of qualifying times
unset($qualifying_times[$loe][$num_of_qualifying_times-1]);
}
$new_num_of_swimmers = count($participating_swimmers);
if($num_of_swimmers == $new_num_of_swimmers) break;
else $num_of_swimmers = $new_num_of_swimmers;
}