Question

我的目的是对在某些日期（第0天到第7天以及第0天到第45天）之间多次发生的行进行计数。代码在下面，因此更容易理解我的意思：

毫无疑问，只有以下COUNT个可以使用。试图创建一个子查询，但失败或返回一些废话。

感谢您的帮助！

Answer 1

使用Case When表达式

SELECT 
    d.personal_id, 
    COUNT (case when d.delivered < d.created + 7 * interval '1 day' then d.deliveryID end) as Deliveries_7D, 
    COUNT (case when d.delivered < d.created + 45 * interval '1 day' then d.deliveryID end) as Deliveries_45D
FROM table_d d
WHERE d.delivered < d.created + 45 * interval '1 day'
GROUP BY d.personal_id
LIMIT 20

Answer 2

您可以通过这种方式使用子查询

select  t1.personal_id, t1.Deliveries_7D, t2.Deliveries_45D
from  (
    select d.personal_id  COUNT (d.deliveryID) as Deliveries_7D
    FROM table_d d

    WHERE d.delivered < d.created + 7 * interval '1 day'

    GROUP BY d.personal_id 

    ) t1  
    inner join  (

    select d.personal_id  COUNT (d.deliveryID) as Deliveries_45D
    FROM table_d d

    WHERE d.delivered < d.created + 45 * interval '1 day'

    GROUP BY d.personal_id 
    ) t2. on t1.personal_id = t2.personal_id

计算一列中不同日期的行

2 个答案: