Position vs named placeholders

bettermysql-namedPlaceholders.php

<?php
  // Assuming that database connection is already open
  // Some variables
  $userid = 1000;
  $country = 'USA';
  
  // Using named placeholders
  $stmt = $db->prepare("SELECT user, email, country FROM users WHERE id > :id AND country = :country")
  
  // The order of objects in the array does not matter
  $stmt->execute(array(':country'=>$country,
                       ':id'=>$id));
?>

bettermysql-positionalPlaceholders.php

<?php
  // Assuming that database connection is already open
  // Some variables
  $userid = 1000;
  $country = 'USA';
  
  // Using positional placeholders
  $stmt = $db->prepare("SELECT user, email, country FROM users WHERE id > ? AND country = ?")
  
  // The first array item will correspond to the first ?, hence "id > 1000"
  // The second array item will correspond to the second ?, hence "country = 'USA'"
  $stmt->execute(array($userid, $country));
?>