text: create table users (
      id varchar(50) not NULL,
      email varchar(50) not NULL UNIQUE,
      passwd varchar(50) not NULL,
      admin bool not NULL,
      name varchar(50) not NULL,
      image varchar(500) not NULL,
      created_at real not NULL,
      PRIMARY KEY (id)
  );
  
  create index users_idx_created_at on users(created_at);
  
  create table blogs (
      id varchar(50) not NULL,
      user_id varchar(50) not NULL,
      user_name varchar(50) not NULL,
      user_image varchar(500) not NULL,
      category varchar(50) not NULL,
      title varchar(50) not NULL,
      digest varchar(50) not NULL,
      content text not NULL,
      created_at real not NULL,
      PRIMARY KEY (id)
  );
  
  create index blogs_idx_created_at on blogs(created_at);
  create index blogs_idx_category on blogs(category);
  
  create table comments (
      id varchar(50) not NULL,
      blog_id varchar(50) not NULL,
      user_id varchar(50) not NULL,
      user_name varchar(50) not NULL,
      user_image varchar(50) not NULL,
      content varchar(500) not NULL,
      created_at real not NULL,
      PRIMARY KEY (id)
  );
  
  create index comments_idx_created_at on comments(created_at);
  