Sorting arrays

[C0d3r]

Hello,

At first, my apologies for not yet knowing the exact php terms which may make the issue slightly more complicated than it actually is.

I am currently working on a game, to which the user data is linked to my database.
Now I want to use parts of the users' data and put that in a highscore list.

The way it works so far:
I load the data of each players in an array, so in other words, each player has its own array, containing the required information. The code looks the following:

for($i=2; $i<$num_players; $i++) //start at 2 in order to skip the admin account (which has an ID of 1 in the database)
{
	$playerID[$i] = mysql_query("SELECT * FROM `tbl_gamestats` WHERE ID='$i'");
	$player[$i] = mysql_fetch_assoc($playerID[$i]);
	$place[$i] = Array("name"=>$player[$i]["username"],"level"=>$player[$i]["level"],"experience"=>$player[$i]["ownexp"],"money"=>$player[$i]["money"]);	
}

Ok, so probably as anyone will be able to figure out, this will return the arrays for each player (containing their name, level, experience and money, where 'i' is equivalent to their ID in the database.

Now here comes the "tricky" part:

I want to sort these arrays on level, from high to low (descending), in a way it still also remembers which username belongs to its corresponding level.

//Sorting code
//What should I put here in order to sort $place on "level"?

And then eventually here print the sorted output in the highscores list.

for($i=0; $i<$num_players-2; $i++) //Depending on how the <sort> function works, I may have to start $i at either 0, 1 or 2
{	
	print_r($place[$i]);
	echo "<br/>";
}

Hopefully one of you can help me solve this problem 🙂

[Derokorian]

Why not print it when you retrieve it from the database?
Why are you running a query in a loop? You can sort with your query, and just select all the rows at once, something like SELECT FROM tbl_gamestats ORDER BY level DESC also you shouldn't use SELECT instead you should list all the columns you need to get data from.

[C0d3r]

Interesting, I did not know MySQL also has a sorting function.

This makes the code less complicated. I do however still have a problem printing out the result.

I now have the following:

<?php

//<link to the database> not required to solve this problem

$result= mysql_query("SELECT `username`, `level`, `ownexp`, `money` FROM `tbl_gamestats` ORDER BY `level` DESC");
$players= mysql_fetch_assoc($result);
print_r($players);
?>

The result, the query is correct - it prints out the player's array with the highest level on top, including its username, level, experience and money value in the form of an array.

Also, for instance

echo $draw["username"]; 

would return the username of the player at #1. However.. here also, how about the rest of the rows?

This is the ONLY player that is printed out. How do can I make the rest show as well?
I assume $result contains the information for all rows, but does that mean mysql_fetch_assoc only works out things out for one single row?

Can this be done in a way of.. say.. $players[<rank>]["key"]?
ie.

$players[1]["username"] 

returns the username of the player at rank 1? (note the Rank, not the ID)

:bemused:

[NogDog]

You need to put the mysql_fetch_assoc() within a while loop, and either output the data of interest on each iteration, or possibly load it into an array for later use, depending on your program design. See example #1 on the [man]mysql_fetch_assoc/man page.

[C0d3r]

NogDog;10999275 wrote:

You need to put the mysql_fetch_assoc() within a while loop, and either output the data of interest on each iteration, or possibly load it into an array for later use, depending on your program design. See example #1 on the [man]mysql_fetch_assoc/man page.

What is it that I would be looping..?
What kind of output does $result have when it is defined as multiple rows and colums?

$result= mysql_query("SELECT `username`, `level`, `ownexp`, `money` FROM `tbl_gamestats` ORDER BY `level` DESC");
$players= mysql_fetch_assoc($result);

I don't seem to have much chance for looping, or ?

[C0d3r]

In fact, I just now figured out what you ment, so the previous question is not neccissary anymore.

$result= mysql_query("SELECT `username`, `level`, `ownexp`, `money` FROM `tbl_gamestats` ORDER BY `level` DESC");

for($i=0; $i<$num_players; $i++)
{
	$players[$i] = mysql_fetch_assoc($result);	
}

This is the way I have it now, and works 🙂

Case solved - Thank you everyone!

[NogDog]

The way I'd probably do it with the old MySQL extension:

$result= mysql_query("SELECT `username`, `level`, `ownexp`, `money` FROM `tbl_gamestats` ORDER BY `level` DESC");
if($result != false) {
    $players = array(); // not strictly necessary, but makes me feel better :)
    while($row = mysql_fetch_assoc($result)) {
        $players[] = $row;
    }
}
else {
    // handle DB error here
}

However, if you use the more modern [man]MySQLi[/man] PHP extension, it has the handy [man]mysqli_fetch_all/man function that makes it even simpler.