postgresql - 存储过程给出错误 : query has no destination for result data

Question

我有一个存储过程，如下所示。我总是认为最后一次选择的结果会自动返回，但是我收到了这个错误，我不知道为什么，有人可以启发我吗？

    CREATE OR REPLACE FUNCTION pGetPlans() RETURNS TABLE (
    title varchar(16),
    full_cost money,
    subtitle varchar(128),
    blurb varchar(128),
    details varchar(128)[],
    final_str text)
AS $$
DECLARE
full_cost      tplan.cost%TYPE;
current_cost   tplan.cost%TYPE;
amount_saved   tplan.cost%TYPE;
percent_saved  float;
monthly_cost   tplan.cost%TYPE;
one_month_cost tplan.cost%TYPE;
you_save       tplan.cost%TYPE;

BEGIN
    select
        cost
    into
        one_month_cost
    from
        tplan
    where
        is_base = true;

    select
        p.title,
        p.cost,
        p.subtitle,
        p.blurb,
        p.details,
        '1 Month Cost is: ' || one_month_cost::text as final_str
    from
        tplan p
    where
        p.status = 'A';
END;
$$ LANGUAGE plpgsql;

谢谢克鲁兹

Answer 1

I always though that the last select's result would be returned automatically

这只适用于使用 sql 语言编写的函数，而不是 plpgsql 和其他语言。

Documentation引用:

SQL functions execute an arbitrary list of SQL statements, returning the result of the last query in the list.

使用RETURN QUERY SELECT...作为最后一条指令，在plpgsql中实现相同的效果。