Search Script for PHP website with MySQL Database - php

Question

I have a PHP website to display products. I need to introduce a 'Search' feature whereby a keyword or phrase can be found among number of products.
I went through number of existing scripts and wrote/modified one for me which though able to connect to database, doesn't return any value. The debug mode throws a warning " mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given ". Seems I am not collecting the query value correctly. The PHP Manuals says that mysqli_query() returns FALSE on failure and for successful SELECT, SHOW, DESCRIBE or EXPLAIN queries mysqli_query() will return a mysqli_result object and for other successful queries mysqli_query() will return TRUE ".
Any suggestions?
<form name="search" method="post" action="search.php">
<input type="text" name="searchterm" />
<input type="hidden" name="searching" value="yes" />
<input type="submit" name="submit" value="Search" />
</form>
<?php
$searchterm=trim($_POST['searchterm']);
$searching = $_POST['searching'];
$search = $_POST['search'];
//This is only displayed if they have submitted the form
if ($searching =="yes")
{
echo 'Results';
//If they forget to enter a search term display an error
if (!$searchterm)
{
echo 'You forgot to enter a search term';
exit;
}
//Filter the user input
if (!get_magic_quotes_gpc())
$searchterm = addslashes($searchterm);
// Now connect to Database
# $db = mysqli_connect('localhost','username','password','database' );
if (mysqli_connect_errno()) {
echo 'Error: Could not connect to the database. Please try again later.';
exit;
}
else {
echo "Database connection successful."; //Check to see whether we have connected to database at all!
}
//Query the database
$query = "SELECT * FROM wp_posts WHERE post_title LIKE '%$searchterm%' OR post_excerpt LIKE '%$searchterm%' OR post_content LIKE '%$searchterm%'";
$result = mysqli_query($db, $query);
if (!$result)
echo "No result found";
$num_results = mysqli_num_rows($result);
echo "<p>Number of match found: ".$num_results."</p>";
foreach ($result as $searchResult) {
print_r($searchResult);
}
echo "You searched for $searchterm";
$result->free();
$db->close();
}

Answer 1

To do your literal search as you have it, you would need to change the code '%{searchterm}%' to '%$searchterm%', since the brackets aren't needed and you were searching for the phrase "{searchterm}." Outside of that you might want to take a look at FULLTEXT search capabilities since you're doing a literal search in your current method.
To make the output look like Google's output you would simply code a wrapper for each search result and style them with CSS and HTML.

Answer 2

I think it should be something like '%$searchterm%', not '%{searchterm}%' in your query. You are not searching for your variable $searchterm in your example.
Google's display uses LIMIT in the query so it only displays a certain amount of results at a time (known as pagination).
This is tested and works. You will need to change 1) db connection info in the search engine class. 2) If you want it to be on separate pages, you will have to split it up. If not, copy this whole code to one page and it will work on that one page.
<?php
class DBEngine
{
protected $con;
// Create a default database element
public function __construct($host = '',$db = '',$user = '',$pass = '')
{
try {
$this->con = new PDO("mysql:host=$host;dbname=$db",$user,$pass, array(PDO::ATTR_ERRMODE => PDO::ERRMODE_WARNING));
}
catch (Exception $e) {
return 0;
}
}
// Simple fetch and return method
public function Fetch($_sql)
{
$query = $this->con->prepare($_sql);
$query->execute();
if($query->rowCount() > 0) {
$rows = $query->fetchAll();
}
return (isset($rows) && $rows !== 0 && !empty($rows))? $rows: 0;
}
// Simple write to db method
public function Write($_sql)
{
$query = $this->con->prepare($_sql);
$query->execute();
}
}
class SearchEngine
{
protected $searchterm;
public function execute($searchword)
{
$this->searchterm = htmlentities(trim($searchword), ENT_QUOTES);
}
public function display()
{ ?>
<h1>Results</h1>
<?php
//If they forget to enter a search term display an error
if(empty($this->searchterm)) { ?>
<h3>Search Empty</h3>
<p>You must fill out search field.</p>
<?php }
else {
$con = new DBEngine('localhost','database','username','password');
$results = $con->Fetch( "SELECT * FROM wp_posts WHERE post_title LIKE '%".$this->searchterm."%' OR post_excerpt LIKE '%".$this->searchterm."%' OR post_content LIKE '%".$this->searchterm."%'");
if($results !== 0 && !empty($results)) { ?>
<p>Number of match found: <?php echo count($results); ?> on search:<br />
<?php echo strip_tags(html_entity_decode($this->searchterm)); ?></p>
<?php
foreach($results as $rows) {
echo '<pre>';
print_r($rows);
echo '</pre>';
}
}
else { ?>
<h3>No results found.</h3>
<?php
}
}
}
}
if(isset($_POST['submit'])) {
$searcher = new SearchEngine();
$searcher->execute($_POST['searchterm']);
$searcher->display();
} ?>
<form name="search" method="post" action="">
<input type="text" name="searchterm" />
<input type="hidden" name="searching" value="yes" />
<input type="submit" name="submit" value="Search" />
</form>