mysql - 运行总计以查找第一个日期达到的总和按组划分

Question

希望有人可以提供帮助，我有一个查询，它执行交易的总和并输出达到总和的日期：

FROM (SELECT * FROM transactions WHERE t_status='paid' 
AND event_id=12345
ORDER BY date_paid) AS base,
         (SELECT @sum := 0) init
WHERE (@sum := @sum + amount - refund_amount - fee) >= 20

这很好用！唯一的问题是它只适用于单个事件 id，我想要为每个事件 id 支付的日期，其中总和大于或等于 20，我尝试了一些变体，包括子查询或连接但没有运气，例如：

SELECT min(a.date_paid),b.event_id FROM
(SELECT  date_paid,event_id
FROM     (SELECT * FROM transactions WHERE t_status='paid' 
ORDER BY date_paid) AS base,
         (SELECT @sum := 0) init
WHERE (@sum := @sum + amount - refund_amount - fee) >= 500) a JOIN events_history b ON a.event_id=b.event_id GROUP BY a.event_id

标签： mysqlsqlaggregate-functionscumulative-sum