wordpress リニューアル時にメディア画像をインポートする（プラグインなし）

include_once './wp-load.php';

//// 旧サイト attachment 抽出
$attachment_ids = [];
$sql = "SELECT
		*
	FROM
		wp_posts_past
	WHERE
		post_type = 'attachment'
";
$past_attachment_posts = $wpdb->get_results($sql);

//// 新サイトへインポート
foreach ($past_attachment_posts as $past_post) {
	$wpdb->insert(
		'wp_posts',
		[
			'post_author' => 1,
			'post_date' => $past_post->post_date,
			'post_date_gmt' => $past_post->post_date_gmt,
			'post_title' => $past_post->post_title,
			'post_status' => $past_post->post_status,
			'comment_status' => 'closed',
			'ping_status' => 'closed',
			'post_password' => '',
			'post_name' => $past_post->post_name,
			'post_modified' => $past_post->post_modified,
			'post_modified_gmt' => $past_post->post_modified_gmt,
			'guid' => $Import->str_replace('ttps://www.pastsite.jp', 'ttps://www.newsite.jp', $past_post->guid),
			'post_type' => $past_post->post_type,
			'post_mime_type' => $past_post->post_mime_type,
		],
		[
			'%d', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s',
		],
	);
	$insert_post_id = $wpdb->insert_id; // 新サイトDBにインサートされた「ID」
	//// 旧サイトpostmeta抽出 *複数あり
	$sql_postmeta = "SELECT
			*
		FROM
			wp_postmeta_past
		WHERE
			post_id = $past_post->ID
	";
	$postmetas = $wpdb->get_results($sql_postmeta);
	foreach ($postmetas as $postmeta) {
		$wpdb->insert(
			'wp_postmeta', // wp_postmeta_test_attachment || wp_postmeta
			[
				'post_id' => $insert_post_id,
				'meta_key' => $postmeta->meta_key,
				'meta_value' => $postmeta->meta_value,
			],
			[
				'%d', '%s', '%s',
			],
		);
	}
}