alter table typecho_comments convert to character set utf8mb4 collate utf8mb4_unicode_ci;
alter table typecho_contents convert to character set utf8mb4 collate utf8mb4_unicode_ci;
alter table typecho_fields convert to character set utf8mb4 collate utf8mb4_unicode_ci;
alter table typecho_metas convert to character set utf8mb4 collate utf8mb4_unicode_ci;
alter table typecho_options convert to character set utf8mb4 collate utf8mb4_unicode_ci;
alter table typecho_relationships convert to character set utf8mb4 collate utf8mb4_unicode_ci;
alter table typecho_users convert to character set utf8mb4 collate utf8mb4_unicode_ci;

/** 定义数据库参数 */
$db = new Typecho_Db('Pdo_Mysql', 'typecho_');
$db->addServer(array (
  'host' => 'localhost',
  'user' => 'user',
  'password' => 'password',
  'charset' => 'utf8mb4', //<-- This
  'port' => '3306',
  'database' => 'database',
), Typecho_Db::READ | Typecho_Db::WRITE);
Typecho_Db::set($db);