PL / pgSQL函数：如何使用execute语句返回表 [英] PL/pgSQL functions: How to return table with an execute statement

问题描述

我有这个 PL / pgSQL 函数，它必须返回一些用户信息。

I've got this PL/pgSQL function which must return some users information.

CREATE OR REPLACE FUNCTION my_function(user_id integer)
  RETURNS TABLE(id integer, firstname character varying
                          , lastname  character varying) AS
$$
DECLARE
    ids character varying;
BEGIN
    ids := '';

    --Some code which build the ids string, not interesting for this issue

    RETURN QUERY EXECUTE 'SELECT users.id, users.firstname, users.lastname
    FROM public.users WHERE ids IN (' || ids || ')';
END;
$$ LANGUAGE plpgsql;

我遇到的问题是函数的结果是这样的单个列表：

The problem I'm facing is that the result of the function is a single columns table like this:

╔═══╦═════════════════════╗
║   ║my_function          ║
╠═══╬═════════════════════╣
║ 1 ║ (106,Ned,STARK)     ║
║ 2 ║ (130,Rob,STARK)     ║
╚═══╩═════════════════════╝

虽然我预计：

While I expected:

╔═══╦════════════╦════════════╦═════════════╗
║   ║ id         ║ firstname  ║ lastname    ║
╠═══╬════════════╬════════════╬═════════════╣
║ 1 ║ 106        ║ Ned        ║ STARK       ║
║ 2 ║ 103        ║ Rob        ║ STARK       ║
╚═══╩════════════╩════════════╩═════════════╝

我认为（但并不确定）问题来自于 EXECUTE 语句，但我无法看到如何处理。

I think (but not sure) the problem comes from the EXECUTE statement, but I can't see how to do otherwise.

有什么想法？ / p>

Any ideas?

推荐答案

你如何执行该功能？它用作select语句。

How are you executing that function? It works as a select statement.

创建表格： public.users

create table public.users (id int, firstname varchar, lastname varchar);

插入一些记录：

Insert some records:

insert into public.users values (1, 'aaa','bbb'),(2,'ccc','ddd');

功能： my_function

function: my_function

CREATE OR REPLACE FUNCTION my_function(user_id integer) RETURNS TABLE(id integer, firstname character varying, lastname character varying) AS $$
    DECLARE
        ids INTEGER[];
    BEGIN
         ids := ARRAY[1,2];
         RETURN QUERY
             SELECT users.id, users.firstname, users.lastname
             FROM public.users
             WHERE users.id = ANY(ids);
    END;
$$ LANGUAGE plpgsql;

现在您可以使用*

select * from my_function(1);

查询结果

Result of query

 id | firstname | lastname 
----+-----------+----------
  1 | aaa       | bbb
  2 | ccc       | ddd

或列名称

select id,firstname,lastname from my_function(1);

结果

Result

 id | firstname | lastname 
----+-----------+----------
  1 | aaa       | bbb
  2 | ccc       | ddd

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