sql server中的每月总和+ PIVOT

Question

我在一个表中有 2 列金额和日期

Amount   |  Date (MM/DD/YYYY)

5         01/01/19
10        02/01/19
10        03/01/19
10        03/21/19
10        04/21/19

预期结果：

01/01    02/01   03/01   04/01
  5        10      20      10

Answer 1

试试下面的查询

  select DECODE(to_char(date), 'MM'), '04', sum(amount) ) AS 01/01,
     DECODE(to_char(date), 'MM'), '05', sum(amount) ) AS 02/01,
     DECODE(to_char(date), 'MM'), '06', sum(amount) ) AS 03/01,
     DECODE(to_char(date), 'MM'), '07', sum(amount) ) AS 04/01,
     DECODE(to_char(date), 'MM'), '08', sum(amount) ) AS 05/01,
     DECODE(to_char(date), 'MM'), '09', sum(amount) ) AS 06/01,
     DECODE(to_char(date), 'MM'), '10', sum(amount) ) AS 07/01,
     DECODE(to_char(date), 'MM'), '11', sum(amount) ) AS 08/01,
     DECODE(to_char(date), 'MM'), '12', sum(amount) ) AS 09/01,
     DECODE(to_char(date), 'MM'), '01', sum(amount) ) AS 10/01,
     DECODE(to_char(date), 'MM'), '02', sum(amount) ) AS 11/01,
     DECODE(to_char(date), 'MM'), '03', sum(amount) ) AS 12/01 from t

Answer 2

如果你知道你想要的列，你可以使用条件聚合（或pivot）：

select sum(case when month(date) = 1 then amount end) as [01/01],
       sum(case when month(date) = 2 then amount end) as [02/01],
       sum(case when month(date) = 3 then amount end) as [03/01],
       sum(case when month(date) = 4 then amount end) as [04/01]
from t
where date >= '2019-01-01' and date < '2020-01-01'

如果您想要一组动态的列，那么您需要一个动态枢轴。单个select 无法做到这一点。