title: "ERROR: query has no destination for result data" in PL/pgSQL function
body: <p>I want to create a function which can be used to insert data into the table <code>uuser</code> and return the <code>uid</code> with data type <code>serial</code>.</p>
  
  <pre><code>CREATE TABLE uuser (
    uid serial PRIMARY KEY
  , user_name text NOT NULL
  , last_login timestamptz NOT NULL DEFAULT current_timestamp
  , real_name text
  , age int
  , city text
  , CHECK (age &gt; 0 and age &lt; 140)
  );
  
  CREATE OR REPLACE FUNCTION ins_uuser(p_user_name text
                                     , p_real_name text
                                     , p_age int
                                     , p_city text)
  RETURNS integer AS
  $$
  BEGIN
  INSERT INTO uuser(user_name, last_login, real_name, age, city)
  VALUES($1, CURRENT_TIMESTAMP, $2, $3, $4)
  RETURNING uid;
  END;
  $$
  LANGUAGE plpgsql VOLATILE;
  
  SELECT ins_uuser('Joker', 'Jack', 18, 'New York') AS uuser_id;
  </code></pre>
  
  <blockquote>
  <pre><code>ERROR:  query has no destination for result data
  CONTEXT:  PL/pgSQL function ins_uuser(text,text,integer,text) line 3 at SQL statement
  </code></pre>
  </blockquote>