sql - Postgresql 复制到循环中变量的 csv 自动错误

Question

我正在尝试从表中导出数据以获取产品相关的 csv 文件。我创建了一个如下所示的函数，但是当我尝试运行它时，Postgres 在包含产品的变量 rec 上抛出错误。任何人都可以协助对我的功能进行故障排除以查找错误吗？当我之前测试它时，如果我将数据插入表中，它会按预期工作。

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;

逻辑上你的循环是加号。