在插件激活挂钩上，我想创建一个表，但下面的代码给出了Uncaught Error. 我只是想知道为什么它没有给出这个错误，因为我正确地包括了update.php.

global $wpdb;

$sql = \'CREATE TABLE IF NOT EXISTS \'.$wpdb->prefix.\'gs_orders(\';
$sql .= \'id BIGINT(20) AUTO_INCREMENT NOT NULL,\';
$sql .= \'order_number VARCHAR(200) NOT NULL,\';
$sql .= \'group_id INT NOT NULL,\';
$sql .= \'group_admin BIGINT(20) NOT NULL,\';
$sql .= \'group_user BIGINT(20) NOT NULL,\';
$sql .= \'product_groups VARCHAR(255),\';
$sql .= \'products VARCHAR(255),\';
$sql .= \'created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,\';
$sql .= \'updated_at DATETIME NULL DEFAULT NULL,\';
$sql .= \'PRIMARY KEY (id),\';
$sql .= \'INDEX (order_number, group_id, group_admin, group_user),\';
$sql .= \')\' . $wpdb->get_charset_collate() . \';\';

require_once ABSPATH . \'/wp-admin/includes/update.php\';
dbDelta($sql);