selecting highest id of an array

[dachshund]

hi,

 

i'm trying to select the highest id in an array, so that if it's the highest one a reply button is displayed.

 

my code so far is

 

<?php
$query = mysql_query("SELECT MAX(`id`) FROM `comments` WHERE `replyto` LIKE '$commentid' AND `moderate` LIKE '0'");		
$maxRow= mysql_fetch_array($query);
$max = $maxRow['id'];		
if($id == $max)	{
?>

<span class="comment_reply">
<a id="<?php echo $commentrows['id']; ?>" />
Reply
</a>
</span>

<?php		
}
?>

 

any help would be great!

[ManiacDan]

...and what's the problem here? 

[dachshund]

the maximum id is not being selected

[Jessica]

1. Use =, not LIKE here.

2. Echo the query first to make sure it looks the way you expect.

3. Check for mysql errors. mysql_query has plenty of examples.

4. Switch to mysqli

[dachshund]

thanks jesirose. i tried those things but it has made no difference.

 

when i echo out $max it is blank.

[Psycho]

thanks jesirose. i tried those things but it has made no difference.

 

when i echo out $max it is blank.

 

Are you getting errors? The only ways I can suspect you are getting an empty value without getting errors is:

  1) The id value in all the matching records is empty

  2) there are no matching records.

 

I suspect #2 is your problem. Always echo your queries out to inspect them before running them. And when encountering such issues just add some debugging logic to output information to help you determine the problem.

$query = "SELECT MAX(`id`)
          FROM `comments`
          WHERE `replyto` = '$commentid'
            AND `moderate` = '0'";
$result = mysql_query($query);
if(!$result)
{
    echo "QUERY FAILED:<br>Query: $query<br>Error: " . mysql_error();
}
else
{
    $max = mysql_result($result, 0);
    //Begin Debugging logic
    $query2 = "SELECT COUNT(`id`)
              FROM `comments`
              WHERE `replyto` = '$commentid'
                AND `moderate` = '0'"
     $result = mysql_query($query2) or die(mysql_error());
     $count = mysql_result($result, 0);
     echo "$query<br>The above query matched $count records";
     //End debugging logic
}

if($id == $max)
{
    echo "<span class='comment_reply'>\n";
    echo "<a id='{$commentrows['id']}'' />Reply</a>\n";
    echo "</span>\n";
}

[dachshund]

thanks psycho, that's useful.

 

i tried that code and it said "the above record matches one record", but still wouldn't echo the reply button.

[Pikachu2000]

There's obviously more code that's relevant to this problem. You should post it also.

[dachshund]

well, it's able to find that there is one matching query. it's just not realising that it's the maximum id in the query.

 

the only other parts of the code that are relevant are '$commentid' and $commentrows['id'], both of which work and echo out perfecty.

 

thanks

[Pikachu2000]

So you want people to blindly guess what the rest of the code does and what control structures, etc. may be affecting the outcome?

[dachshund]

here we go:

 

<?php
$commentsql="SELECT * FROM comments WHERE articleid LIKE $id AND moderate LIKE 0 AND replyto LIKE 0 ORDER BY id ASC";
$commentresult=mysql_query($commentsql) or die (mysql_error());
while($commentrows=mysql_fetch_array($commentresult)){

$date = date('d F y', strtotime($commentrows['datetime']));
$sql="SELECT * FROM content WHERE id='$id'";
$result = mysql_query($sql) or die (mysql_error());
$rows=mysql_fetch_array($result);
$articleid=$rows['id'];
$replyto = $commentrows['id'];

if (strlen($http) > 3) {
$http = substr($http, 0, 7);
}			
?>

<script type="text/javascript">


$(function(){
$('#<?php echo $commentrows['id']; ?>').click(function(){ 
	$("#randomdiv<?php echo $commentrows['id']; ?>").load('http://www.website.co.uk/reply_comment.php', {'id' : '<?php echo $commentrows['id'];?>'})
});
});

$(function(){
$('#reply<?php echo $commentrows['id']; ?>').click(function(){ 
	$("#randomdiv<?php echo $commentrows['id']; ?>").load('http://www.website.co.uk/reply_comment.php', {'id' : '<?php echo $commentrows['id'];?>'})
});
});

</script>

<div id="posted_comments">

<ul>
    
    	<li class="comment_text">
        
        <? echo $commentrows['comment']; ?>
        
        </li>
            
    	<li class="username">

        <?php echo $commentrows['name']; ?> 
        
        <span class="comment_date">
        <?php

	echo 'Posted ';
	$dateNew = strtotime($commentrows['datetime']);
	if (timePassed($dateNew) == '')	{
	echo 'just now';
	}else	{
	echo timePassed($dateNew);
	}
	if (timePassed($dateNew) == 'yesterday' OR timePassed($dateNew) == '')	{
	}else	{
	echo ' ago';
	}

	echo ' ';
	?>
        </span>
	     
        <span class="comment_reply">
        <a id="<?php echo $commentrows['id']; ?>" />
        Reply
        </a>
        </span>
        
        <div class="clear"></div>
        
	</li>
    
    </ul>

</div>

<?php
$commentid = $commentrows['id'];
$replycommentsql="SELECT * FROM comments WHERE replyto LIKE $commentid AND moderate LIKE 0 ORDER BY id ASC";
$replycommentresult=mysql_query($replycommentsql) or die (mysql_error());
while($replycommentrows=mysql_fetch_array($replycommentresult)){
?>

<div id="reply_comments_wrap">

<div id="posted_reply_comments">

<ul>
    
    	<li class="comment_text">
        
        <? echo $replycommentrows['comment']; ?>
        
        </li>
            
    	<li class="username">

        <?php echo $replycommentrows['name']; ?> 
        
        <span class="comment_date">
        <?php

	echo 'Posted ';
	$dateNew = strtotime($replycommentrows['datetime']);
	if (timePassed($dateNew) == '')	{
	echo 'just now';
	}else	{
	echo timePassed($dateNew);
	}
	if (timePassed($dateNew) == 'yesterday' OR timePassed($dateNew) == '')	{
	}else	{
	echo ' ago';
	}

	echo ' ';
	?>
        </span>
        
        <?php
        $query = mysql_query("SELECT MAX[`id`] FROM `comments` WHERE `replyto` LIKE '$commentid' AND `moderate` LIKE '0' ORDER BY id ASC");
	$maxRow = mysql_fetch_array($query);
	$max = $maxRow['id'];
	if($replycommentrows['id'] == $max)	{
	?>

	<span class="comment_reply">
        <a id="reply<?php echo $commentrows['id']; ?>" />
        Reply
        </a>
	</span>

	<?php		
	}
	?>
        
        <div class="clear"></div>
        
	</li>
    
    </ul>

</div>

<div class="clear"></div>

</div>

<?php
}
?>

<div id="randomdiv<?php echo $commentrows['id']; ?>"></div>

<?php

}

mysql_close();

?>

<script type="text/javascript">
    
function validateForm()
{
var x=document.forms["comment"]["n"].value
if (x==null || x=="" || x=="Your name...")
{
$('#comment_wrap').prepend($('<div class="comment_wrong">Please fill in all fields.</div>').fadeIn('slow').delay(1000).fadeOut('slow'));
return false;
}
$('#comment_wrap').prepend($('<div class="comment_answer">Thank you! Your comment will be approved shortly.</div>').fadeIn('slow').delay(1000).fadeOut('slow'));
$('#comment_container input[type=text]').attr('value', 'Your name...');
$('#comment_container textarea').attr('value', 'Your comment...');
}

// wait for the DOM to be loaded 
$(document).ready(function() {
// bind 'commenter' and provide a simple callback function 
    $('#commenter').ajaxForm( { beforeSubmit: validateForm } );
});
        
</script>


<div id="comment_wrap">

<div id="comment_container">

<ul>

        <form name="comment" method="post" id="commenter" action="http://www.website.co.uk/comment_posted.php?id=<?php echo $id; ?>">
        
        <li>
        
        <input type="text" placeholder="Your name..." class="text_name_email" name="n">
        
        </li>
        
        <li>
        
        <textarea class="text_area" name="c" placeholder="Your thoughts..."></textarea>
        
        </li>
        
        <li>
        
        <input type="submit" value="Post" class="post_comment">
        
        </li>
        
        </form>
        
        </li>
    
    
   	</ul>

</div>

</div>

[dachshund]

worked it out

 

it is :

 

$query = mysql_query("SELECT MAX(`id`) AS `id` FROM `comments` WHERE `replyto` LIKE '$commentid' AND `moderate` LIKE '0' ORDER BY id ASC");