text: create table chats
  (
      id          int auto_increment,
      user_id     int default 0 not null,
      friend_id   int default 0 not null,
      message     text          not null,
      create_time int default 0 not null,
      update_time int default 0 not null,
      constraint chat_id_uindex
          unique (id)
  )
      comment '聊天记录';
  