问如何查询postgresql/sql中数组字段的订阅

EN

CREATE TABLE IF NOT EXISTS books (
  bookid uuid PRIMARY KEY,
  categories uuid[],
  name text,
  author text,
  releasedate timestamp
);

CREATE TABLE IF NOT EXISTS categories (
  categoryid uuid PRIMARY KEY,
  name text
);

CREATE TABLE IF NOT EXISTS users (
  userid uuid PRIMARY KEY,
  name text
);

CREATE TABLE IF NOT EXISTS catsubscribers (
  categoryid uuid REFERENCES categories,
  userid uuid REFERENCES users,
  PRIMARY KEY (categoryid,  userid)
);

CREATE TABLE IF NOT EXIST bookcats (
  bookid uuid REFERENCES books,
  categoryid uuid REFERENCES categories,
  PRIMARY KEY (bookid, categoryid)
);

CREATE OR REPLACE FUNCTION getBooksBySubscribedCategory(me uuid, ofst integer, lim integer)
RETURNS TABLE(bookid uuid, categories uuid[], name text, author text, releasedate timestamp) AS $$
  DECLARE cid RECORD;
  BEGIN
    FOR cid IN (SELECT categoryid FROM catsubscribers WHERE userid = me)
    LOOP
      RETURN QUERY SELECT bks.bookid, bks.categories, bks.name, bks.author, bks.releasedate
      FROM (SELECT bookid, categories, name, author, releasedate FROM books WHERE bookid IN (SELECT bookid FROM bookcats WHERE categoryid = cid ) AS bks
      ORDER BY releasedate DESC
      OFFSET ofst
      LIMIT lim;
    END LOOP;
    RETURN;
  END;
$$ LANGUAGE plpgsql;