Postgres函数:返回多个表 [英] Postgres function: return multiple tables

问题描述

是否可以从postgres函数返回多个不同类型的结果集?

Is it possible to return several result sets of different types from postgres function?

类似的东西:

CREATE OR REPLACE FUNCTION getUserById()
RETURNS setof ???
AS
$$
BEGIN

return query select id, name /* and other columns */ from users where id = 1;
return query select id, phone_number from user_phones where user_id = 1

END
$$
LANGUAGE plpgsql;

我不想使用加入，因为可以为用户使用多个电话.同样，最好避免使用游标. 在MS SQL中是可能的，而我想在postgres中做同样的事情.

I don't want to use joins because several phones for user are possible. Also it would be great to avoid using cursors. It's possible in MS SQL and I want to do the same thing in postgres.

推荐答案

搜索之后，找不到任何更好的解决方案，例如使用游标.我假设您已经看过这本书了: https://blog.dsl-platform.com/multiple-result-sets-alternatives-in-postgres-3/

After the seek, could not find any better solutions as use of cursors. I assume you have seen this one already: https://blog.dsl-platform.com/multiple-result-sets-alternatives-in-postgres-3/

CREATE FUNCTION load_page(_session INT) RETURNS setof refcursor AS
$$
DECLARE c_top_items refcursor;
DECLARE c_shopping_cart refcursor;
BEGIN
    OPEN c_top_items FOR
        SELECT t.name, t.description
        FROM top_item t
        ORDER BY t.popularity DESC
        LIMIT 10;
    RETURN NEXT c_top_items;
    OPEN c_shopping_cart FOR
        SELECT c.product_id, c.product_name, c.quantity
        FROM shopping_cart c
        WHERE c.session_id = _session
        ORDER BY c.id;
    RETURN NEXT c_shopping_cart;
END;
$$ LANGUAGE plpgsql;

并致电:

BEGIN;
SELECT load_page(mySession);
FETCH ALL IN "<server cursor 1>";
FETCH ALL IN "<server cursor 2>";
COMMIT;

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