Postgresql复制到csv循环中的变量出现自动错误

Question

我正在尝试从一个表导出数据以获得产品级的csv文件。我已经创建了一个函数，如下所示，但是Postgres在我试图运行它时，在包含产品的变量rec上抛出了一个错误。有没有人可以帮我排查函数的故障，找出错误？当我之前测试它时，如果我将数据插入到一个表中，它就会像预期的那样工作。

CREATE or replace FUNCTION exportdata() 
RETURNS SETOF record AS
$$
DECLARE
 rec text;
BEGIN
 FOR rec IN 
(
Select distinct t.products from trndailyprices as t
) 
 LOOP
    Copy (
    Select * from trndailyprices as t
    where t.products = rec   ---1st record is product1
    order by t.effectivedate) 
    To 'C:/testQ/' ||rec || '.csv' With CSV;---expected file is product1.csv for 1st record
 END LOOP;
END;
$$ LANGUAGE plpgsql;

Answer 1

 Copy (Select * from trndailyprices as 
    order by effectivedate) To 'C:/testQ/test.csv' With CSV;

从逻辑上讲，你的循环是加的。