CREATE TABLE post (
  id BIGINT PRIMARY KEY NOT NULL,
  description TEXT NOT NULL,
  posted_date DATETIME NOT NULL,
  crawled_date DATETIME NOT NULL
);

CREATE TABLE image (
  id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
  post_id BIGINT NOT NULL,
  url TEXT NOT NULL,
  FOREIGN KEY (post_id) REFERENCES post(id)
);

CREATE TABLE video (
  id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
  post_id BIGINT NOT NULL,
  url TEXT NOT NULL,
  FOREIGN KEY (post_id) REFERENCES post(id)
);