PHP Forum

**Llama** · 12-02-2005, 06:04 AM

hi,

I do a SELECT on a table, and put it into a while loop.

There is 30 entries that can be displayed but I only want to display 5 entries at a time, and i would like to have a next button & a previous button at the bottom where you display the next 5 or previous 5 entries.

How do I do this in PHP?

Thanx!

**Nahele** · 12-02-2005, 09:37 PM

I had a photo gallery project similar to this. It's not to hard. Basically you want the link to be something like this:

thispage.php?page=3

now you will read the value of the page variable and skip the desired number of entries in accordance with the page (you can use a loop for this), in this case skipping the first ($_GET['page'] - 1) * 5 entries. Then have a loop to display the next 5. You will want to make sure that the next and prev buttons are not present when on the last and first page respectively.

If you still can't get it to work I'll post up an example that you can configure for what you need.

**Llama** · 12-03-2005, 10:02 AM

Would you please post the example?

I do not really understand what you mean... sorry..

**Nahele** · 12-03-2005, 08:00 PM

I appologize that I have not had a chance to formally check this...but it should give you a good idea of what is going on...and if anyone sees any errors, please point them out.

PHP Code:


			
<html>
<body>
<?php

//$results = your mySQL query here

//if the form www.domain.com/thispage.php
if (!isset($_GET['page'])) {
    $pageNum = 1;
}
//if the form www.domain/thispage.php?page=4
else {
    $pageNum = $_GET['page'];
}

//determine the number of entries to skip assuming 5 entries per page
$skipValue = ($pageNum - 1) * 5;

//skips through a certain number of entries determined by $skipValue
for ($i = 0; $i < $skipValue; i++) {
    $temp = mysql_fetch_array($results);
}

//display the next 5 entries
for ($i = 1; $i <= 5; i++) {
  //check to make sure $row exists from the $results
    if($row = mysql_fetch_array($results)) {
        print $row[0]."<br>";
        //you will need to add additional columns to display here
    }
}

if ($pagenum != 1) {
    print '<a href="www.domain.com/thispage.php?page='.($pagenum - 1).'">Prev&nbsp;&nbsp;</a>';
}
if ($pagenum != 5 {
    print '<a href="www.domain.com/thispage.php?page='.($pagenum + 1).'">Next</a>';
}
?>
</body>
</html>

**Llama** · 12-07-2005, 12:17 PM

I know that this is going to sound really stupid... but i can't seem to get this right!

Is there any possibillity for somebpdy to explain to me ow this code works.... cause I am really lost!

Thanx!!

**0beron** · 01:41 PM

Skipping through the results isn't the best way of doing pages. MySQL provides the LIMIT and OFFSET clauses to do this:

PHP Code:


			
<?php

//Connect to your database,
//YOU WILL NEED TO FILL THIS BIT IN

//Get the page number from the URL, or set it to 1 if the URL doesn't 
//have page set to anything.
if(isset($_GET['page'])) {
  $page = $_GET['page'];
}
else {
  $page = 1;
}

$num_per_page = 5;

//Calculate the starting item from the page number and the num per page
$start = ($page-1)*$num_per_page +1;

//Get the right number of items from the right place in the db.
$query="SELECT * FROM test3 LIMIT $num_per_page OFFSET $start";
$result = mysql_query($query) or die(mysql_error());

//Start a counter to display the item numbers
$i = $start;

//Loop over the results
while($row = mysql_fetch_array($result)) {
  echo "[item " . $i . "]: ";
  echo $row[0] . "<br/>";
  $i++;
}

//Print the Next and Prev links
if($page > 1) {
  echo '<a href="'
    . $_SERVER['PHP_SELF'] . "?page=" . ($page-1) 
    . '"><--Prev </a>';
}
if(mysql_num_rows($result) == $num_per_page) {
  echo '<a href="' 
    . $_SERVER['PHP_SELF'] . "?page=" . ($page+1) 
    . '"> Next--></a>';
}

?>

You'll need to fill in the top bit with your database connection (mysql_connect or whatever)
You'll also need to change the table name from test3 to whatever your table is.

This prints a very basic list of items and two links. You could extend it very easily to print nice tables or something.

Also when there are an exact multiple of five items in the database, this script adds an extra page which shouldn't be there. Getting rid of that is possible but would make this nice simple example a lot more messy.

I've tested this and put quite a few comments in it, let me know if any part of it needs clarifying....