text: create table comments (
  	id varchar(64) not null,
  	video_id varchar(64),
  	author_id int(10),
  	content text,
  	time datetime default current_timestamp, primary key(id)
  );
  
  create table sessions (
  	session_id varchar(64) not null,
  	TTL tinytext,
  	login_name varchar(20)
  );
  alter table sessions add primary key (session_id(64));
  
  create table users (
  	id int unsigned not null auto_increment,
  	login_name varchar(20),
  	pwd text not null,
  	unique key (login_name),
  	primary key (id)
  );
  
  create table video_del_rec (
  	video_id varchar(64) not null,
  	primary key (video_id)
  );
  
  create table video_info (
  	id varchar(64) not null,
  	author_id int(10),
  	name text,
  	display_ctime text,
  	create_time datetime default current_timestamp,
  	primary key (id)
  );
  