PostgreSQL function returning multiple result sets

Question

Is it possible to return multiple result sets from a Postgres function, like in MSSQL:

CREATE PROCEDURE test

AS

SELECT * FROM first_table

SELECT * FROM se         


        

Answer 1

Yes.

Example:

test=# create function x () returns setof integer language plpgsql as $$ begin return next 1; return next 2; end $$;
CREATE FUNCTION
test=# select * from x();
 x 
---
 1
 2
(2 rows)

You can of course use an existing table/view or a custom type for the returned type.

Example using language SQL:

test=# create table customer (name varchar, birth_date date);
CREATE TABLE
test=# create function y () returns setof customer language sql as $$ 
select * from customer
union all
select * from customer
$$;
CREATE FUNCTION
test=# insert into customer values ('joe', now()::date);
INSERT 0 1
test=# insert into customer values ('jill', now()::date);
INSERT 0 1
test=# select * from y();
 name | birth_date 
------+------------
 joe  | 2009-04-16
 jill | 2009-04-16
 joe  | 2009-04-16
 jill | 2009-04-16
(4 rows)

See here for doc