Question

我正在使用Presto SQL并尝试计算按国家/地区和customer_status细分的每天登录网站的客户数量？将状态从“新”更新为“返回”需要2天。结果应如下所示：

date        country     status  total_count
2019-08-01  usa         new      1
                        return   null
            canada      new      1
                        return   1

table a : country of customers
login_date      id      country
2019-08-01      1       usa
2019-08-01      4       canada
2019-08-01      5       canada
2019-08-02      1       usa
2019-08-02      3       usa
2019-08-02      4       usa
2019-08-03      1       usa
2019-08-03      2       canada
2019-08-03      3       usa
2019-08-03      4       usa
2019-08-03      5       canada

...

table b : daily status of customers. 
**It takes 2 days to update the status from ‘new’ to ‘return’  
purchase_date       id      customer_status
2019-08-01      5           return
2019-08-02      4           new
2019-08-02      5           return
2019-08-03      1           return
2019-08-03      2           new
2019-08-03      3           return
2019-08-04      4           return

...

关于如何联接两个具有不同日期的表的任何建议？我认为该表应在同一日期加入，但要延迟2天。

SELECT a.date,
a.country,
b.customer_status,
COUNT(id)
FROM table_a a
LEFT JOIN table_b b
ON (a.id = b.id AND ‘how should I join on date that’s 2 days delay?’)
GROUP BY 1,2

非常感谢您！

Answer 1

您需要这样做，DATE_ADD(日期, INTERVAL 2 DAY)

SELECT a.date,
a.country,
b.customer_status,
COUNT(id)
FROM table_a a
LEFT JOIN table_b b
ON (a.id = b.id AND a.login_date = DATE_ADD(b.purchase_date, INTERVAL 2 DAY))
GROUP BY 1,2

如何联接具有相同ID但不同日期范围的2个表？

1 个答案: