<?php
require 'config/db.php';
$columns = ['consignee_email' => 'VARCHAR(100)', 'consignee_gst' => 'VARCHAR(20)'];
foreach ($columns as $col => $type) {
    $stmt = $pdo->query("SHOW COLUMNS FROM tbl_bookings LIKE '$col'");
    if (!$stmt->fetch()) {
        echo "Adding $col...\n";
        $pdo->exec("ALTER TABLE tbl_bookings ADD COLUMN $col $type AFTER consignee_phone");
    } else {
        echo "$col exists.\n";
    }
}
?>