PostgreSQL Return Joined Results of Select

I'm learning PostgreSQL and was wondering if I can put long selects in stored procedures like this one:

CREATE OR REPLACE FUNCTION api.book_list()
RETURNS TABLE (
  id         BIGINT,
  published  DATE,
  category   VARCHAR,
  author     VARCHAR,
  name       VARCHAR
) AS $
BEGIN
  SELECT
    b.id,
    b.published,
    c.name AS category,
    b.author,
    b.name
  FROM
    schemas.book AS b
  JOIN
    schemas.category AS c
  ON
    c.id = b.category_id;
END;
$
LANGUAGE plpgsql;

It is supposed to return select from two joined tables.

It gives the following error:

select * from api.book_list();
ERROR:  query has no destination for result data
HINT:  If you want to discard the results of a SELECT, use PERFORM instead.
CONTEXT:  PL/pgSQL function "book_list" line 3 at SQL statement

Use RETURN QUERY SELECT ...;.

PostgreSQL is complaining because you aren't specifying what to return. Also, since you aren't actually passing parameters to the function this could also be accomplished by a view.

StackExchange Database Administrators Q#31251, answer score: 2