PHP - Limit An Array

Unless buffer overflows or breaking out of code to perform a new command are problems that have been solved....

I am trying to figure out the proper PHP method for setting a boundary on a variable within a script. I have this variable $name which is fed a value from $_POST['name'] from a form field. Now this form field is limited in the HTML to accept only 20 characters, but someone could easily edit the form or outgoing post data. So I want to know how to limit the variable size in the script. In other languages it could be something like this: var name(20). So how do I do that in PHP?

Hello friends,

if i've database table (mytable) has the following ids
1
2
3
4
5
6

and i want to get it with limit the first (1 to 3 ) only

Code: [Select]
$sql ="select *  from  mytable LIMIT 3"; this will show the first 3 (1,2,3)

how then i write code that shows which is after 3
so it shows me
4
5
6

and if there any way i can say
Code: [Select]
$sql ="select *  from  mytable LIMIT (first half of ids)"; and (shows 1,2,3..ect till half)
Code: [Select]
$sql ="select *  from  mytable LIMIT (second half of ids)";
will (shows 4,5,6...ect till end)

 
thank you

im using the floowing code to pull all alerts from the database. as you can see i have 3 types of alertsd. Profile alerts, forum alerts and topic alerts. They are sorted and placed on the screen under their respective header. However i want to limit it so it only displays 4 of each type of alert. I cant use LIMIT in the query because that would limit all alerts meaning only 4 alerts in total would show up and i just need to limit each alert type. any ideas?


$alert_query = $link->query("SELECT 
                            a.a_aid, a.a_alert_type, a.a_time_alerted, 
                            a.a_fid, a.a_poster, a_alert_read,
                            a.a_tid, c.f_name as cat_name,
                            f.f_fid, f.f_name,
                            t.t_name,
                            u.u_avatar, u.u_avatar_cropped
                            FROM ".TBL_PREFIX."alerts as a
                            LEFT JOIN ".TBL_PREFIX."forums as f
                            ON (f.f_fid = a.a_fid)
                            LEFT JOIN ".TBL_PREFIX."topics as t
                            ON (t.t_tid = a.a_tid)
                            LEFT JOIN ".TBL_PREFIX."forums as c
                            ON (c.f_fid = f.p_id) 
                            LEFT JOIN ".TBL_PREFIX."users as u
                            ON (u.u_username = a.a_poster)
                            WHERE a.a_user_name = '$user_name'
                            ORDER BY a_time_alerted
                            ") or die(print_link_error());
        $alert_info = $alert_query->fetchAll();
        
        $pm_alert_list = '';
        $num_pm_alerts = 0;
        $num_forum_alerts = 0;
        $num_topic_alerts = 0;
        
        foreach($alert_info as $key => $val)
        {
            $alert_info[$key]['a_alert_read'] == 0 ? $color = '#f5dfaf' : $color = '#f4f4f4';
            
            // if alert is a profile message alert
            if($alert_info[$key]['a_alert_type'] == 1)
            {    
                $pm_alert_list .= '<dd style="background:'.$color.';" class="alert" id="alert-'.$alert_info[$key]['a_aid'].'"><p class="alert_intro">';
                $pm_alert_list .= '<input type="checkbox" class="pm_checkbox" id="pm_checkbox-'.$alert_info[$key]['a_aid'].'" />'.profile_link($alert_info[$key]['a_poster']).' posted on your wall</p>';
                $pm_alert_list .= '<p class="alert_time"> on '.asf_date($alert_info[$key]['a_time_alerted'],'full').'</p>';
                $pm_alert_list .= '</dd>';
                $num_pm_alerts++;
            }
            
            if($alert_info[$key]['a_alert_type'] == 2)
            {    
                $forum_alert_list .= '<dd style="background:'.$color.';" class="alert" id="alert-'.$alert_info[$key]['a_aid'].'"><p class="alert_intro">';
                $forum_alert_list .= '<input type="checkbox" class="pm_checkbox" id="pm_checkbox-'.$alert_info[$key]['a_aid'].'" /><strong><a href="'.$config['asf_root'].'category/'.create_url($alert_info[$key]['cat_name']).'/forum/'.create_url($alert_info[$key]['f_name']).'">'.$alert_info[$key]['f_name'].'</a></strong> has a new topic</p>';
                $forum_alert_list .= '<p class="alert_time"> '.asf_date($alert_info[$key]['a_time_alerted'],'full').'</p>';
                $forum_alert_list .= '</dd>';
                $num_forum_alerts++;
            }
            
            if($alert_info[$key]['a_alert_type'] == 3)
            {    
                $topic_alert_list .= '<dd style="background:'.$color.';" class="alert" id="alert-'.$alert_info[$key]['a_aid'].'"><p class="alert_intro">';
                $topic_alert_list .= '<input type="checkbox" class="pm_checkbox" id="pm_checkbox-'.$alert_info[$key]['a_aid'].'" /><strong><a href="'.$config['asf_root'].'category/'.create_url($alert_info[$key]['cat_name']).'/forum/'.create_url($alert_info[$key]['f_name']).'/topic/'.create_url($alert_info[$key]['t_name']).'">'.$alert_info[$key]['t_name'].'</a></strong> has a new post</p>';
                $topic_alert_list .= '<p class="alert_time"> '.asf_date($alert_info[$key]['a_time_alerted'],'full').'</p>';
                $topic_alert_list .= '</dd>';
                $num_topic_alerts++;
            }
        }

This code works fine without the LIMIT 5, but it lists all the results.  With the LIMIT

Code: [Select]
$query = 'SELECT * FROM wp_playerRank WHERE year="2011" LIMIT 5 ORDER BY rankClass ASC';
$results = mysql_query($query);
while($line = mysql_fetch_assoc($results)) {


Here is the error I'm getting:

Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource in /home/jwrbloom/public_html/resources/players/rank2011_top5.php on line 26

hello,

I have a form i am using for a raffle that i have weekly. the problem is i want to limit how many times they can register.  I am using a basic form that collects name, email, and IP ( which is hidden ). When it gets submitted there is time stamp as well using this

date("m/d/y : H:i:s", time()


I would like to restict registering by one hour at a time. can you please give me some help with this. I have thought of maybe using cookies, but some of my smarter members can bypass that. So i think i will either use email or IP .

any help would be very appreciated

hello, is there a wat to limit the following to only the first 25 characters?

$customername=$row1["customer"];

thanks

I am in need of a alimit on the explode() fucntion but reading through the php explode manual on php.net there doesn't seem to be one that is right for me.

Basically I'm making a command system for a php chat and it has a command called ban.
I have code that find out if it is a command or a normal string, I also have code that starts to break up the command into segments that can be places in the database.

I want to split up "ban user lengthID "Reason why you were banned"" using explode($string, " ") but I notice that that will also break up the "reason why you are banned".

How do I get it to split up the command but NOT thereason why you were banned string?

Confusing I know, Please ask any questions that would help me explain it better Thanks in advance!

Hi,

I have a timestamp mysql field that I'm trying to see if something happened within a time limit. The field is updated with the time when the action is complete so I just need to figure out how to see if it's within a time. I currently have a defined variable set titled "MAX_RESPONSE_TIME" and that's in seconds. By default "MAX_RESPONSE_TIME" is equal to 300 seconds. How can I see if a mysql timestamp field is within 300 seconds?

Im wondering if someone can shed some light on possibly the best way to do this.
I currently have a website which recieves 26000-37000 visits a month. The host got on my case about to many MySql connections and with help from someone here decided a cache system was best. the cache system is now in place and only updates if the cached file is older than 5 days. I am still recieving high connections to my database and wonder if it is spam as i have a search box. the search box once filled in redirects to a page which queries the database for the keyword and displays results and because it was just selecting and not inserting into database i didnt go for the captcha. this is why i suspect spam, I have thought about limiting the amount of search queries per time limit by ip but I am unsure of how to tackle this and if it will help against spam bots?

a google search has only found an answer which stores every visitors ip in a database and keeps count there which I cant see the benefit as it is creating more work for the DB. I have thought maybe creating a session variable that increments with every search and when searching checks this value but I am not to sure if this would help as it would be down to cookie settings.

can anyone shed some light on a possible solution to this.

I am not expecting you to write this for me but for now just to help with the best way to tackle the problem.

Thank you for your time.

Hi,

This line of code works just fine for me:
$sql_quest = 'SELECT id, username FROM user ORDER BY id ASC LIMIT 0, 30';

I want to be able to set the integer values dynamically and I thought something like this would work:
$sql_quest = 'SELECT id, username FROM user ORDER BY id ASC LIMIT' . $my_int_value . ',' . $my_int_value + 30;

But it doesn't... Any ideas?

Alright so I have some code for pagination... the problem is on the middle pages it will display double the number of results... (IE if its supposed to display 5, it displays 10)

Code: [Select]
// Number of messages per page:
$user_message_number = 5;

$page = $_GET['page'];
if($page <= 1){
$low = 0;
$high = $user_message_number;
} else {
$low = ($page - 1) * $user_message_number;
$high = $page * $user_message_number;
}

$messages = mysql_query("SELECT * FROM messages WHERE recipient='$user_id' ORDER BY id DESC LIMIT $low, $high") or die(mysql_error());
while($pull_messages = mysql_fetch_array($messages)) {
// Displays content
}

That's all of the code that would directly effect the outcome... Any thoughts/comments/suggestions are greatly appreciated.

Hi,

I'm fairly new to all of this and I'm not quite sure what to do. I'm trying to create a field in my database that's 4 hours and 10 minutes into the future from the current time. What data type do I set my field as in the mysql database? How would I populate that mysql field via php.. would I use something like NOW(), or use the php date() function? Also, how would I be able to tell if my field has "expired" (the 4 hours and 10 minutes has elapsed)?

Hi guys I have a problem. I limit the displayed rows by 10 (which works) and then a link saying "next" or "previous"
The link itself works, but the site always just displays teh first 10 data entries.
What do I do wrong?
Thank you!

Code: [Select]
<?php
$host="****"; // Host name
$username="****"; // Mysql username
$password="****"; // Mysql password
$db_name="****"; // Database name
$tbl_name="sp_users"; // Table name

// Connect to server and select database.
mysql_connect("$host", "$username", "$password")or die("cannot connect");
mysql_select_db("$db_name")or die("cannot select DB");

//$sql="SELECT * FROM $tbl_name ORDER BY user_id";
$sql="SELECT * from sp_users,sp_schools where sp_users.user_id=sp_schools.school_id ORDER BY school_name LIMIT 0, 10";
$result=mysql_query($sql);
$num_rows=mysql_num_rows($result);
?>
<?PHP
//check if the starting row variable was passed in the URL or not
if (!isset($_GET['startrow']) or !is_numeric($_GET['startrow'])) {
  //we give the value of the starting row to 0 because nothing was found in URL
  $startrow = 0;
//otherwise we take the value from the URL
} else {
  $startrow = (int)$_GET['startrow'];
}
?>
<?PHP
//this part goes after the checking of the $_GET var
$fetch = mysql_query("SELECT * FROM sp_users,sp_schools where sp_users.user_id=sp_schools.school_id LIMIT $startrow, 10")or
die(mysql_error());
?>
<style type="text/css">
<!--
.style2 {font-weight: bold}
.style3 {
font-family: Arial, Helvetica, sans-serif;
color: #000000;
}
.style10 {font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; color: #000000; }
#Layer1 {
position:absolute;
left:803px;
top:36px;
width:65px;
height:28px;
z-index:1;
}
#Layer2 {
position:absolute;
left:707px;
top:19px;
width:143px;
height:39px;
z-index:1;
}
#Layer3 {
position:absolute;
left:247px;
top:463px;
width:175px;
height:53px;
z-index:2;
}
-->
</style>

<title>User overview</title>
</html>
<div id="Layer2">
  <form action="<?= $_SERVER['PHP_SELF'] ?>" method="post">
<input type="hidden" name="foo" value="<?= $foo ?>" />
<input type="submit" name="submit" value="Refresh" />
</form></div>
<div id="Layer3"><?PHP
//now this is the link..
echo '<a href="'.$_SERVER['PHP_SELF'].'?startrow='.($startrow+10).'">Next</a>';
?>
<?PHP
$prev = $startrow - 10;

//only print a "Previous" link if a "Next" was clicked
if ($prev >= 0)
    echo '<a href="'.$_SERVER['PHP_SELF'].'?startrow='.$prev.'">Previous</a>';
?></div>
<table width="779" border="0" align="left" cellpadding="0" cellspacing="1" bgcolor="#996600">
<tr>
<td width="777">
 
    <div align="left">
      <table width="779" border="1" cellspacing="0" cellpadding="3">
        <tr>
          <td colspan="6" align="center"><div align="center" class="style1 style3"><strong>SchoolPorta.com Users / Total: <?php echo $num_rows ?></strong></div></td>
          </tr>
        <tr>
          <td width="342" align="center"><span class="style2">school</span></td>
          <td width="62" align="center"><span class="style2">Name</span></td>
          <td width="104" align="center"><span class="style2">Lastname</span></td>
          <td width="130" align="center"><span class="style2">Email</span></td>
      <td width="64" align="center"><span class="style2">Update</span></td>
        </tr>
        <?php
while($rows=mysql_fetch_array($result)){
?>
        <tr>
          <td><span class="style10"><? echo $rows['school_name']; ?></span></td>
  <td><span class="style10"><? echo $rows['user_first_name']; ?></span></td>
          <td><span class="style10"><? echo $rows['user_surname']; ?></span></td>
          <td><span class="style10"><a href="mailto:<?php echo $rows['user_login']; ?>"><?php echo $rows['user_login']; ?></a></span></td>
          <td align="center"><a href="update.php?id=<? echo $rows['user_id']; ?>" class="style10">update</a></td>
        </tr>
        <?php
}
?>
      </table>
    </div></td>
</tr>
</table>

<div align="left">
  <p>&nbsp;   </p>
  <p>&nbsp;</p>
  <p>&nbsp;</p>
  <p>
    <?php
mysql_close();
?>
  </p>
</div>

This topic has been moved to MySQL Help.

http://www.phpfreaks.com/forums/index.php?topic=342142.0