CREATE TABLE users (
    user_id SERIAL PRIMARY KEY,
    nick text UNIQUE NOT NULL,
    hash text NOT NULL,
    email text NOT NULL,
    created_on timestamp NOT NULL DEFAULT now()
);

CREATE TABLE rooms (
    room_id SERIAL PRIMARY KEY,
    name text UNIQUE NOT NULL,
    created_on timestamp NOT NULL
);

CREATE TABLE messages (
    message_id SERIAL PRIMARY KEY,
    user_id integer NOT NULL REFERENCES users,
    room_id integer NOT NULL REFERENCES rooms,
    content text NOT NULL,
    created_on timestamp NOT NULL
);

CREATE TABLE user_session (
    session_id bigint PRIMARY KEY,
    user_id integer NOT NULL REFERENCES users,
    id_address text NOT NULL,
    ttl timestamp NOT NULL
);