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Easy, Simple Paging Using PHP

Easy & Simple Paging using PHP. Here is the result: (DB has 8records, Rows per page is set to 5, and we're on page 2)

Paging usually takes a while but here we will do it quickly and cleanly.

Your page will be named page.php. And when we want to switch pages we will make it page.php?pg=2.
Im sure you've seen this before. Anyways lets dive in.

I use shorthand to clean stuff up, but basically shorthand is

$returnvalue=(condition ? "true" : "false");
Example:

$is_loggedin=(isset($_SESSION["loggedin"]) ? 1 : 0);
After this statement, if the session variable is set, $is_loggedin will equal 1, else it will equal 0.

At the top of your PHP page type the following:

<?php
/*paging*/
Line 1: $pg=(isset($_GET["pg"]) && is_numeric($_GET["pg"]) && $_GET["pg"]>0 ? $_GET["pg"] : 1);
Line 2: $rowsperpage=10;
Line 3: $offset=($pg>1 ? ($pg-1)*$rowsperpage : 0 );
Line 4: $limitstr=" LIMIT $offset, $rowsperpage";
?>

Explanation:
First of all Limit is : LIMIT $startrowid, $number of entries to return
So LIMIT 55, 5 means start at row 55 and return 5 rows (55, 56, 57, 58, 59)

Line 1: If in the query string the pg is set e.g page.php?pg=4, and it is numeric, and greater than 0 we will assign the value of $_GET["pg"] to our $pg variable. If it is not set, or it is not numeric, or zero or less, we set the $pg variable to 1.
Line 2: We set our rows per page
Line 3: If the page is greater than 1, we set the offset to ($pg-1)*rowsperpage. If the page is 1 or less, we set offset to 0.
Line 4: We create the limit string for the sql statement. This will output something like LIMIT x, y.
(rowsperpage set to 10)

In this case page.php?pg=1
$pg = 1;
$offset = 0;
$rowsperpage=10;
$limitstr="LIMIT 0, 10"; //this string will pull 10 rows starting from row 0 (the first row) (rows 0-9)

In this case page.php?pg=3
$pg=3;
$offset= (3-1) * 10; //offset calculates to 20
$limitstr="LIMIT 20, 10"; //this string will pull 10 rows starting from and including row 20 (rows 20-29)

Ok. Now that we got that out of the way.

We will use a simple query, then we will attach our new limit string (looking at case 2 above)
$sql="SELECT * FROM MEMBERS $limitstr"; //sql = "SELECT * FROM MEMBERS LIMIT 20,10";
$res=mysql_query($sql);
while($row=mysql_fetch_array($res)){

//processing if you need to
}

We also need to know the total count for this table
$sql="SELECT COUNT(memberid) FROM MEMBERS";
$res=mysql_query($sql);
$row=mysql_fetch_array($res);
$total = $row[0];

Now we know the total count.

So we need to calculate the number of pages. That is done by this formula:
($total/$rowsperpage);
Now in the case of 26 members and 5 rows per page. Using this formula 26/5 = 5.2pages, so we need to round up!

$maxpage=ceil($total/$rowsperpage); //max page is now 6.

Ok, we got everything set up Just need to print out our paging!
Wherever you want your paging setup add this:

<?php
print '<div class="paging"><ul>';
for($i=1; $i<=$maxpage; $i++){
  if($pg==$i)
     print '<li><span>'.$i.'</span></li>';
  else
     print '<li><a href="?pg='.$i.'">'.$i.'</a></li>';
}
print "</ul></div>";
?>

Then we can do some nice styling (Mess around with margins to setup spacing)
CSS
div.paging {text-align: center; margin-top: 5px;}
div.paging span{font-weight: bold;}
div.paging ul{overflow: hidden;}
div.paging ul li{width: 10px; float: left; margin: 0px 10px 5px 0px;}

This will page across until it hits the edge of the div, then it will move to the next line.

ENJOY and comment !