CREATE TABLE `wp_comments` (
  `comment_ID` bigint(20) UNSIGNED NOT NULL,
  `comment_post_ID` bigint(20) UNSIGNED NOT NULL DEFAULT '0',
  `comment_author` tinytext COLLATE utf8mb4_unicode_520_ci NOT NULL,
  `comment_author_email` varchar(100) COLLATE utf8mb4_unicode_520_ci NOT NULL DEFAULT '',
  `comment_author_url` varchar(200) COLLATE utf8mb4_unicode_520_ci NOT NULL DEFAULT '',
  `comment_author_IP` varchar(100) COLLATE utf8mb4_unicode_520_ci NOT NULL DEFAULT '',
  `comment_date` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  `comment_date_gmt` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  `comment_content` text COLLATE utf8mb4_unicode_520_ci NOT NULL,
  `comment_karma` int(11) NOT NULL DEFAULT '0',
  `comment_approved` varchar(20) COLLATE utf8mb4_unicode_520_ci NOT NULL DEFAULT '1',
  `comment_agent` varchar(255) COLLATE utf8mb4_unicode_520_ci NOT NULL DEFAULT '',
  `comment_type` varchar(20) COLLATE utf8mb4_unicode_520_ci NOT NULL DEFAULT '',
  `comment_parent` bigint(20) UNSIGNED NOT NULL DEFAULT '0',
  `user_id` bigint(20) UNSIGNED NOT NULL DEFAULT '0'
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_520_ci;

ALTER TABLE `wp_comments`
  ADD PRIMARY KEY (`comment_ID`),
  ADD KEY `comment_post_ID` (`comment_post_ID`),
  ADD KEY `comment_approved_date_gmt` (`comment_approved`,`comment_date_gmt`),
  ADD KEY `comment_date_gmt` (`comment_date_gmt`),
  ADD KEY `comment_parent` (`comment_parent`),
  ADD KEY `comment_author_email` (`comment_author_email`(10));