从网上找到例子：
可以说，RETURN NEXT要用在循环中:
例子一：
数据准备：
CREATE TABLE foo (fooid INT, foosubid INT, fooname TEXT);
INSERT INTO foo VALUES (1, 2, 'three');
INSERT INTO foo VALUES (4, 5, 'six');
生成函数：
CREATE OR REPLACE FUNCTION getAllFoo() RETURNS SETOF foo AS
$BODY$
DECLARE
r foo%rowtype;
BEGIN
FOR r IN SELECT * FROM foo
WHERE fooid > 0
LOOP
-- can do some processing here
RETURN NEXT r; -- return next row of SELECT
END LOOP;
RETURN;
END
$BODY$
LANGUAGE 'plpgsql';
运行结果：
pgsql=# SELECT * FROM getallfoo();
fooid | foosubid | fooname
-------+----------+---------
1 | 2 | three
4 | 5 | six
(2 rows) pgsql=#
例子二：
数据准备：
CREATE TABLE test (textcol varchar(10), intcol int);
INSERT INTO test VALUES ('a', 1);
INSERT INTO test VALUES ('a', 2);
INSERT INTO test VALUES ('b', 5);
INSERT INTO test VALUES ('b', 6);
生成函数：
CREATE OR REPLACE FUNCTION ReturnNexting(pText Text) RETURNS SETOF test AS $$
DECLARE
rec RECORD;
BEGIN
FOR rec IN SELECT * FROM test WHERE textcol = pText LOOP
RETURN NEXT rec;
END LOOP;
RETURN;
END;
$$
LANGUAGE plpgsql;
运行结果：
pgsql=# SELECT * FROM ReturnNexting('a');
textcol | intcol
---------+--------
a | 1
a | 2
(2 rows)
pgsql=#