postgresql 如何编写不返回任何内容的 postgres 存储过程？
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How do I write a postgres stored procedure that doesn't return anything?
提问by ScArcher2
How do I write a simple stored procedure in postgres that doesn't return a value at all? Even with a void return type when I call the stored procedure I get a single row back.
如何在 postgres 中编写一个根本不返回值的简单存储过程？即使在调用存储过程时使用 void 返回类型，我也会返回单行。
CREATE FUNCTION somefunc(in_id bigint) RETURNS void AS $$
BEGIN
DELETE from test_table where id = in_id;
END;
$$ LANGUAGE plpgsql;
采纳答案by Michael Krelin - hacker
It's not the function that returns value, it's the SELECTyou used to call it. If it doesn't return any rows, it doesn't run your function.
不是返回值的函数，而是SELECT您用来调用它的函数。如果它不返回任何行，则它不会运行您的函数。
回答by Michael Krelin - hacker
You can achieve "nothing returned" by abusing set-returning functions:
您可以通过滥用 set-returning 函数来实现“无返回”：
Simple function:
简单的功能：
create function x () returns setof record as $$
begin
return;
END;
$$ language plpgsql;
Now you can:
现在你可以：
# select x();
x
---
(0 rows)
In case it doesn't work for you (sorry, I'm using 8.5), try with this approach:
如果它对您不起作用（抱歉，我使用的是 8.5），请尝试使用以下方法：
# create function x (OUT o1 bool, OUT o2 bool) returns setof record as $$
begin
return;
END;
$$ language plpgsql;
CREATE FUNCTION
The parameters are irrelevant, but:
参数无关紧要，但是：
- You need > 1 of them
- They have to be named
- 你需要 > 1 个
- 他们必须被命名
And now you can:
现在你可以：
# select * from x();
o1 | o2
----+----
(0 rows)
回答by George Silva
You are doing just fine. You dont need to add anything else.
你做得很好。您无需添加任何其他内容。
The result of the row is null, so it is a void return.
该行的结果为空，因此它是一个空返回。
I don't think theres something you can do about that. Checking my void functions all of them are just like yours.
我认为你对此无能为力。检查我的 void 函数，它们都和你的一样。
returns void as $$ and no return statement in code block.
将 void 作为 $$ 返回，并且代码块中没有 return 语句。
