如何在PostgreSQL的函數中返回查詢結果的行？

Question

我已經嘗試了很多次以下的教程，但失敗了。 有人可以給我一些例子嗎？ 這裏是我的代碼，它提示說：「錯誤：無效的類型名稱‘SETOF記錄’」

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; 

Answer 1

方式來聲明集返回函數，我記得的時刻：

--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()