PHP PDO ORDER BY - Sorting Data

Sorting Data (ORDER BY)

The ORDER BY clause is used to sort results by one or more columns. By default, it sorts in ascending order (ASC), but we can also use descending order (DESC).

EXAMPLE

<?php
$server = "localhost";
$username = "root";
$password = "";
$database = "pdo_database";

try {
    $connection = new PDO("mysql:host=$server;dbname=$database;charset=utf8mb4", $username, $password);
    $connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    // SQL query with sorting
    // ASC means ascending (A-Z), DESC would mean descending (Z-A).
    $sql = "SELECT first_name, last_name FROM users ORDER BY last_name ASC";
    $result = $connection->query($sql);

    echo "<ul>";
    // Using fetch(PDO::FETCH_ASSOC) to convert each row into an associative array.
    while ($row = $result->fetch(PDO::FETCH_ASSOC)) {
        echo "<li>" . $row['last_name'] . " " . $row['first_name'] . "</li>";
    }
    echo "</ul>";

} catch (PDOException $e) {
    echo "Error: " . $e->getMessage();
}

$connection = null;
?>

RESULT

The result will be displayed here...

In PDO, we execute this with a simple query() statement and then output the sorted data using a loop. This is extremely useful when displaying lists of users or products.

ASC sorts from A to Z or from smallest to largest.

DESC sorts from Z to A or from largest to smallest.

You can sort by multiple columns simultaneously (e.g., first by last name, then by first name).