Question

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How to sort the results of this code?

Im making a search feature which allows a user to search a question and it will show the top 5 best matching results by counting the number of matching words in the question.
Basically I want the order to show the best match first which would be the question with the highest amount of matching words.
Here is the code I have.

<?php
include("config.php");
$search_term = filter_var($_GET["s"], FILTER_SANITIZE_STRING); //User enetered data
$search_term = str_replace ("?", "", $search_term); //remove any question marks from string
$search_count = str_word_count($search_term);  //count words of string entered by user
$array = explode(" ", $search_term); //Seperate user enterd data



foreach ($array as $key=>$word) {
$array[$key] = " title LIKE '%".$word."%' "; //creates condition for MySQL query
}

$q = "SELECT * FROM posts WHERE  " . implode(' OR ', $array); //Query to select data with word matches
$r = mysql_query($q);
$count = 0; //counter to limit results shown
    while($row = mysql_fetch_assoc($r)){
        $thetitle = $row['title']; //result from query
        $thetitle = str_replace ("?", "", $thetitle);  //remove any question marks from string
        $title_array[] = $thetitle;  //creating array for query results
        $newarray = explode(" ", $search_term); //Seperate user enterd data again
            foreach($title_array as $key => $value) {
                $thenewarray = explode(" ", $value); //Seperate each result from query
                $wordmatch = array_diff_key($thenewarray, array_flip($newarray));
                $result = array_intersect($newarray, $wordmatch);
                $matchingwords = count($result); //Count the number of matching words from
                                                 //user entered data and the database query
            }

if(mysql_num_rows($r)==0)//no result found
    {
    echo "<div id='search-status'>No result found!</div>";
    }
else //result found
    {
    echo "<ul>";
        $title = $row['title'];
        $percentage = '.5'; //percentage to take of search word count
        $percent = $search_count - ($search_count * $percentage); //take percentage off word count
        if ($matchingwords >= $percent){
        $finalarray = array($title => $matchingwords);

        foreach( $finalarray as $thetitle=>$countmatch ){


?>
    <li><a href="#"><?php echo $thetitle ?><i> &nbsp; <br />No. of matching words: <?php echo $countmatch; ?></i></a></li>
<?php


                }
                $count++;
        if ($count == 5) {break;
        }
                }else{



            }
    }
echo "</ul>";
}

?>

When you search something it will show something like this.



Iv put the number of matching words under each of the questions however they are not in order. It just shows the first 5 questions from the database that have a 50% word match. I want it to show the top 5 with the most amount of matching words.

What code would I need to add and where would I put it in order to do this?

Thanks

Answer 1

Here’s my take on your problem. A lot of things have been changed:

• mysql_ functions replaced with PDO
• usage of anonymous functions means PHP 5.3 is required
• main logic has been restructured (it’s really hard to follow your result processing, so I might be missing something you need, for example the point of that $percentage)

I realize this might look complicated, but I think that the sooner you learn modern practices (PDO, anonymous functions), the better off you will be.

<?php
/**
 * @param string $search_term word or space-separated list of words to search for
 * @param int $count
 * @return stdClass[] array of matching row objects
 */
function find_matches($search_term, $count = 5) {
    $search_term = str_replace("?", "", $search_term);
    $search_term = trim($search_term);
    if(!strlen($search_term)) {
        return array();
    }
    $search_terms = explode(" ", $search_term);

    // build query with bind variables to avoid sql injection
    $params = array();
    $clauses = array();

    foreach ($search_terms as $key => $word) {
        $ident = ":choice" . intval($key);
        $clause = "`title` LIKE {$ident}";
        $clauses []= $clause;
        $params [$ident] = '%' . $word . '%';
    }

    // execute query
    $pdo = new PDO('connection_string');
    $q = "SELECT * FROM `posts` WHERE  " . implode(' OR ', $clauses);
    $query = $pdo->prepare($q);
    $query->execute($params);
    $rows = $query->fetchAll(PDO::FETCH_OBJ);

    // for each row, count matches
    foreach($rows as $row) {
        $the_title = $row->title;
        $the_title = str_replace("?", "", $the_title);

        $title_terms = explode(" ", $the_title);
        $result = array_intersect($search_terms, $title_terms);
        $row->matchcount = count($result);
    }

    // sort all rows by match count descending, rows with more matches come first
    usort($rows, function($row1, $row2) {
        return - ($row1->matchcount - $row2->matchcount);
    });

    return array_slice($rows, 0, $count);
}
?>

<?php
    $search_term = filter_var($_GET["s"], FILTER_SANITIZE_STRING);
    $best_matches = find_matches($search_term, 5);
?>

<?php if(count($best_matches)): ?>
    <ul>
    <?php foreach($best_matches as $match): ?>
        <li><a href="#"><?php echo htmlspecialchars($match->title); ?><i> &nbsp; <br/>No. of matching words: <?php echo $match->matchcount; ?></i></a></li>
    <?php endforeach; ?>
    </ul>
<?php else: ?>
    <div id="search-status">No result found!</div>
<?php endif; ?>