CREATE TABLE IF NOT EXISTS thread(
	id INTEGER PRIMARY KEY,
	title TEXT NOT NULL,
	time TIMESTAMP WITH TIME ZONE NOT NULL
);

CREATE TABLE IF NOT EXISTS post(
	thread_id INTEGER REFERENCES thread(id) ON DELETE CASCADE NOT NULL,
	id INTEGER PRIMARY KEY,
	name TEXT NOT NULL,
	trip_code TEXT,
	subject TEXT,
	time TIMESTAMP WITH TIME ZONE NOT NULL,
	file_url TEXT,
	file_name TEXT,
	file_md5 TEXT,
	body TEXT NOT NULL
);

CREATE TABLE IF NOT EXISTS link(
	link_from INTEGER REFERENCES post(id) ON DELETE CASCADE NOT NULL,
	link_to INTEGER REFERENCES post(id) ON DELETE CASCADE NOT NULL
);

CREATE TABLE IF NOT EXISTS tag(
	post_id INTEGER REFERENCES post(id) ON DELETE CASCADE NOT NULL,
	name TEXT NOT NULL
);