我的代码如下所示。

$result = $wpdb->query($sql);
if ( $result ) {
  wp_redirect( "http://www.example.com/contact-us");
  exit();
}

Warning: Cannot modify header information - headers already sent by (output started at /var/www/html/wordpressplugin/wp-admin/includes/misc.php:1281) in /var/www/html/wordpressplugin/wp-includes/pluggable.php on line 1296

$result = $wpdb->query($sql);
if ( $result ) {
  ob_start();
  wp_redirect( "http://www.example.com/contact-us");
  ob_end_flush();
  exit();
}