如何在“string_agg”中为窗口函数（postgresql）排序字符串？

Question

我有两张表：“debt_period”和“payments”。我需要从他们那里看一看。有一个时期可以是几次支付的情况。因此，在这种情况下，我必须将付款金额汇总在一列中，并在另一列中列出逗号分隔的日期。 我使用string_agg（to_char（p.payment_date，'DD.MM.YYYY'）和窗口函数。 这工作正常。问题是字符串中的日期不是按时间顺序排列的。我如何订购它们？

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

尝试用用这个：

变化

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

通过

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

最终结果

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