Display image on php mysql blog based on username of post - php

Question

Thanks in advance!
I have a simple mysql and php blog that I built based on a tutorial I found online. What I would like to be able to do, but have no idea how to go about it, is this:
I would like a picture (avatar) to be displayed with each comment on each post. The picture that is chosen would be based off of the name in the Posted By: area of the comment. So for instance: Let's say me, the admin, leaves a comment on the thread. My name is automatically pulled in via a '$_SESSION' variable so I don't have to worry about entering that each time. When the comment is displayed on the blog thread page, it shows Commented on By: Admin. This name is stored in the db and pulled in with the a php echo statement.
So what I want this avatar code to be able to do is
1) look at the area where the Commented on By: text is
2) read the text
3) see that it says Admin and display the admin.png image next to it. If it sees anything other than Admin in the Commented on By: area, then it will display something like guest.png
Here is a snippet of code I found in my stackoverflow and google searches. It works but it pulls in the guest image 6 times, then the actual admin.png image, and then the guest image 3 more times. And it displays this way on EACH comment on EACH thread! And when I add a new thread and a new comment to that thread, it adds the guest image again at the end of the multiple images being displayed on each comment. Did I set it up wrong?
<?
$sql = "SELECT comment_user FROM comments";
$result = mysql_query($sql) or die(mysql_error());
if (mysql_num_rows($result) != 0) {
$counter = $starting + 1;
$pathImg = "images/";
while ($row = mysql_fetch_array($result)) {
//calculate url image
$pathFile = $pathImg . $row['comment_user'] . ".png";
if (!file_exists($pathFile)) {
$pathFile = $pathImg . "guest.png";
}
?>
<img src="<?=$pathFile?>" alt="<?=$row['comment_user']?>">
</p>
<?
$counter++;
}
}
?>
This displays out as (Guest Image)(Guest Image)(Guest Image)(Guest Image)(Guest Image)(Guest Image)(Admin Image)(Guest Image)(Guest Image)(Guest Image).
Any help on throwing something together would be great! Trying to keep it simple to!
EDIT:
This is how the comments are displayed, along with the code from FlyingGuy's answer.
<?php
foreach ($post['comments'] as $comment){
$commentCount = 0 ;
$sql = "SELECT comment_user FROM comments";
$result = mysql_query($sql) or die(mysql_error());
while ($row = mysql_fetch_array($result)) {
$commentCount++ ;
$pathImg = "images/";
$pathFile = $pathImg . $row['comment_user'] . ".png";
if (!file_exists($pathFile)) {
$pathFile = $pathImg . "guest.png";
}
echo "<img src=\"". $pathFile ."\" alt=\"". $row['comment_user'] ."\"\><br>";
}
?>
<h4>By <?php echo $comment['user']; ?> on <?php echo $comment['date']; ?></h4>
<p><?php echo $comment['body']; ?></p>
<hr />
<?php
}
?>
This is how the functions look for displaying and adding comments:
function get_comments($pid){
$pid = (int)$pid;
$sql = "SELECT `comment_body` AS `body`, `comment_user` AS `user`, DATE_FORMAT(`comment_date`, '%m/%d/%Y') AS`date` FROM `comments` WHERE `post_id` = {$pid}";
$comments = mysql_query($sql);
$return = array();
while (($row = mysql_fetch_assoc($comments)) !== false){
$return[] = $row;
}
return $return;
}
// adds a comment
function add_comment($pid, $user, $body){
if (valid_pid($pid) === false){
return false;
}
$pid = (int)$pid;
$user = mysql_real_escape_string(htmlentities($user));
$body = mysql_real_escape_string(nl2br(htmlentities($body)));
mysql_query("INSERT INTO `comments` (`post_id`, `comment_user`, `comment_body`, `comment_date`) VALUES ({$pid}, '{$user}', '{$body}', NOW())");
return true;
}
?>

Answer 1

Look what you are trying to do is select the image that matches the name of the user in the current row of your result set. So you will set your image file variable as appropriate for each row and you are sending that to the browser.
For starters and can see the probability of case issues here. Are all user names forced to lower case and all image names forced to lower case? If this is on a linux box that is a land mine on windows not so much, but this should be taken into account.
It will set an image name for each row of your queries result set so it will look like:
[image] [comments]
[image] [comments]
[image] [comments]
if you have three rows in your result set.'
Personally I avoid all of the turning php on and off all over the place. Concat a single string and then simply echo it out for each row. So I would code it like so:
<?
$commentCount = 0 ;
$sql = "SELECT comment_user FROM comments";
$result = mysql_query($sql) or die(mysql_error());
while ($row = mysql_fetch_assoc($result)) {
$commentCount++ ;
$pathFile = $pathImg . $row['comment_user'] . ".png";
if (!file_exists($pathFile)) {
$pathFile = $pathImg . "guest.png";
}
echo "<img src=\"". $pathFile ."\" alt=\"". $row['comment_user'] ."\"\><br>";
}
So I have eliminated a lot of things from your code example like counters etc. You don't really need to check and see if there are rows since the while loop simply will not execute of there are no rows so you will simply have a question of comment with no subordinate comments and it will only send the image link if there are comments.
No if it were me doing this I would create an avatar file name is the user table and store the path to those as part of the system configuration which would be part of the global set of variables that are always present. Your query would then join in the users table and the image name or guest image would be in your result set. A bit more complex but much cleaner and it simplifies your code.
One of the reasons I don;t like dynamic typing. $row was being mutated to an array of ALL the rows..