How do I go through the result of a parameterized query?

Question

I'm trying to go through the result of a paremeterized query in PHP. I'm trying this way

//creating a prepared statement
        $stmt = $mysqli->stmt_init();
        $query = "SELECT pcode,price,description FROM products WHERE description like ? ORDER BY PRICE";
        $stmt->prepare($query);

        $search_criteria = '%'.$search_criteria.'%';                
        $stmt->bind_param('s', $search_criteria);
        $stmt->execute();   

        $i=0;
        while($stmt->fetch())
        {
            if ($i++%2 == 0) $trow = "even"; else $trow = "odd"; 
                echo "              <tr class='{$trow}'>";
                echo "                  <td>{$row['pcode']}</td><td>{$row['price']}</td><td>{$row['description']}</td>";
                echo "              </tr>";
                        
        }   

        if ($i==0) {
            echo "<tr class='even'><td colspan='3'><h3>No Results.</h3></td></tr>";
        }

But my code is entering the if statement. How can I go through the result? The database is MySQL.

<?php
$conn = mysql_connect($dbhost, $dbuser, $dbpass) or die('Error connecting to mysql');
mysql_select_db($dbname) or die('Did you <a href="setupreset.php">setup/reset the DB</a>? <p><b>SQL Error:</b>' . mysql_error($conn) . '<p><b>SQL Statement:</b>' . $query);

function execute_query($the_query){
    global $conn;
    $result = mysql_query($the_query) or die('<font size=2><b>SQL Error:</b>' . mysql_error($conn) . '<br/><p><b>SQL Statement:</b>' . $the_query . '<br/>Did you run <i>setupreset.php</i> to setup/reset the DB?</font>');
    return $result;
}
?>

Answer 1

You need to bind the result to some variables:

$query = "SELECT pcode,price,description FROM products WHERE description like ? ORDER BY PRICE";
$stmt = $mysqli->prepare($query);

$search_criteria = '%'.$search_criteria.'%';                
$stmt->bind_param('s', $search_criteria);
$stmt->execute();   

$i=0; $pcode; $price; $description;
$stmt->bind_result($pcode, $price, $description);

while($stmt->fetch()) {
    if ($i++%2 == 0) 
        $trow = "even"; 
    else 
        $trow = "odd"; 
    echo "              <tr class='{$trow}'>";
    echo "                  <td>{$pcode}</td><td>{$price}</td><td>{$description}</td>";
    echo "              </tr>";
}