如何在「string_agg」中爲窗口函數（postgresql）排序字符串？

Question

我有兩張表：「debt_period」和「payments」。我需要從他們那裏看一看。有一個時期可以是幾次支付的情況。因此，在這種情況下，我必須將付款金額彙總在一列中，並在另一列中列出逗號分隔的日期。 我使用string_agg（to_char（p.payment_date，'DD.MM.YYYY'）和窗口函數。 這工作正常。問題是字符串中的日期不是按時間順序排列的。我如何訂購它們？

CREATE MATERIALIZED VIEW base.v_period_payments AS 
SELECT DISTINCT 
dp.card_id, 
dp.year, 
dp.month, 
dp.debt_amount, 
string_agg(to_char(p.payment_date, 'DD.MM.YYYY'), ', ') OVER (PARTITION BY p.period_id) AS 
pay_dates 
FROM base.debt_period dp 
LEFT JOIN base.payments p on (p.period_id = dp.id) 
WHERE dp.card_id = '№001137' 
ORDER BY dp.card_id 

Answer 1

嘗試用用這個：

變化

LEFT JOIN base.payments p on (p.period_id = dp.id) 

通過

LEFT JOIN (select * from base.payments order by period_id,payment_date) p on (p.period_id = dp.id) 

最終結果

CREATE MATERIALIZED VIEW base.v_period_payments AS 
SELECT DISTINCT 
dp.card_id, 
dp.year, 
dp.month, 
dp.debt_amount, 
string_agg(to_char(p.payment_date, 'DD.MM.YYYY'), ', ') OVER (PARTITION BY p.period_id) AS 
pay_dates 
FROM base.debt_period dp 
LEFT JOIN (select * from base.payments order by period_id,payment_date) p on (p.period_id = dp.id) 
WHERE dp.card_id = '№001137' 
ORDER BY dp.card_id