text: create table "user"
  (
      id       serial primary key,
      username varchar unique not null,
      password varchar        not null
  );
  
  create table snippet
  (
      id          serial primary key,
      contents    varchar   not null,
      highlighted varchar   not null default '',
      language    varchar   not null,
      author      int       not null,
      likes       int       not null default 0,
      dislikes    int       not null default 0,
      createdAt   timestamp not null,
      constraint fk_author foreign key (author) references "user" (id)
  );
  
  create table comment
  (
      id        serial primary key,
      contents  varchar   not null,
      snippet   int       not null,
      author    int       not null,
      createdAt timestamp not null,
      constraint fk_author foreign key (author) references "user" (id),
      constraint fk_snippet foreign key (snippet) references snippet (id)
  );
  
  create table vote
  (
      snippet int not null,
      "user"  int not null,
      vote    int not null,
      primary key (snippet, "user")
  );
  