I've tried following tutorials for many times but failed. Could someone give me some examples please? Here is my code, it prompts that "ERROR:invalid type name 'SETOF RECORD'"
create or replace function find() returns SETOF RECORD
as $$
declare A SETOF RECORD;
begin
A=(
select x,y
from .......
)
CASE WHEN EXISTS A
THEN returns query A
ELSE returns query (
select x,y
from ......
)
END;
end;
$$ language plpgsql;
Ways to declare set returning function that I remember at the moment:
--example 1
create or replace function test() returns SETOF RECORD
as $$
begin
RETURN QUERY SELECT * FROM generate_series(1,100);
end;
$$ language plpgsql;
--test output
select * from test() AS a(b integer)
--example 2
create or replace function test2() returns TABLE (b integer)
as $$
begin
RETURN QUERY SELECT * FROM generate_series(1,100);
end;
$$ language plpgsql;
--test output
select * from test2()
--example 3
create or replace function test3() returns SETOF RECORD
as $$
declare
r record;
begin
FOR r IN SELECT * FROM generate_series(1,100) LOOP
RETURN NEXT r;
END LOOP;
end;
$$ language plpgsql;
--test output
select * from test3() AS a(b integer);
--example 4
create or replace function test4() returns setof record
as $$
SELECT * FROM generate_series(1,100)
$$ language sql;
--test output
select * from test4() AS a(b integer);
--example 5
create or replace function test5() returns setof integer
as $$
begin
RETURN QUERY SELECT * FROM generate_series(1,100);
end;
$$ language plpgsql;
--test output
select * from test5()
--example 6
create or replace function test6(OUT b integer, OUT c integer) RETURNS SETOF record
as $$
begin
RETURN QUERY SELECT b.b, b.b+3 AS c FROM generate_series(1,100) AS b(b);
end;
$$ language plpgsql;
--test output
select * from test6()
FULL JOIN, UNION or DISTINCT ON would work, depending on query. I think that it doesn't have anything to do with function declaration. You can't store SETOF RECORD in variable.