How to php pagination of results obtained from this database - php

Question

I am a beginner in php.
I visualize in my html page the results obtained with this php code, and now I want to paginate the results and limit your search to 6 items per page. How can I get this? My php code is as follows:
<?php
$k = $_GET['k'];
$terms = explode(" ", $k);
$query = "SELECT * FROM table_name WHERE ";
$i = 0;
foreach ($terms as $each){
$i++;
if ($i == 1)
$query .= "keywords LIKE '%$each%' ";
else
$query .= "OR keywords LIKE '%$each%' ";
}
// connect
mysql_connect("hostname","databaseUser","databasePassword");
mysql_select_db("databaseName");
$query = mysql_query($query);
$numrows = mysql_num_rows($query);
echo "<p><strong>Totale: {$numrows} risultati trovati</strong></p></br>";
if ($numrows > 0){
while ($row = mysql_fetch_assoc($query)){
$id = $row['id'];
$title = $row['title'];
$description = $row['description'];
$keywords = $row['keywords'];
$link = $row['link'];
$date = $row['date'];
$caption = $row['caption'];
echo "<h4><a href='$link'>$title</a></h4>";
echo "<em>$description</em></br></br>";
echo "$caption</br>";
echo "$link</br></br>";
echo "<em>$date</em></br></br>";
}
}
else
echo "NO result found for \"<p><strong>$k</strong></p>\"";
// disconnect
mysql_close();
?>

Answer 1

Pagination is a problem that most of us have tried to solve over the years.
You can build your own library to do this but you'll almost definitely be re-inventing the wheel and might not spot/handle some of the special cases.
If you're using a framework I'd suggest using the built in paginator, if not you could look at using something like http://pear.php.net/package/Pager which is a PEAR package.

Answer 2

You need to add a page variable into your code. The easiest way to to this is via $_GET, just like you grabbed keywords, so your url should look something like this:
foo.php?k=keywords%20here&p=1
Where p is the current page number.
Then you just need to add a limit to your search results so that you only grab 6, and the correct 6 at that. Something like this:
$query .= ' LIMIT '.(6*($pageNum - 1)).' 6';
This statement tells SQL to start at the first entry for the given page, and grab 6 results. We subtract 1 from the page number so that page 1 starts at entry 0 instead of entry 6.
The result of this code:
page | statement | Rows Grabbed
---------------------------------
1 | LIMIT 0 6 | 1-6
2 | LIMIT 6 6 | 7-12
3 | LIMIT 12 6 | 13-18
---------------------------------
and so on...
You might need to check that $_GET['p'] is an integer before you put it in $pageNum, so that you don't run into runtime issues trying to multiply a string by 6.
If you ever want to change the results per page, simply replace the 6's in that statement with the desired number of results per page, e.g.
$query .= ' LIMIT '.($numResults*($pageNum - 1)).' '.$numResults;
That way you can set your desired number of results with another variable, say $_GET['n'] or something similar, and have even better control.
EDIT:
You should probably add error checking:
$pageNum = (is_numeric($_GET['p']) ? intval($_GET['p']) : 1);
which says if GET[p] is numeric, set pageNum to the integer value of GET[p]. Otherwise, set pageNum to 1.
Also, You have a few errors in the way that you put variables into strings. There are two ways to join a variable into a string, you can either use double quotes and curly braces, like so:
$string = "this string has {$variable} in it";
Or you can concatenate with periods, using either single or double quotes likes so:
$string = 'this string has ' . $variable . " in it";
You have this problem in your foreach loop when you append the query, and also further down where you output your results.