在oracle中替代pivot

Question

我需要根据同一列上的不同条件计算记录数。以下是示例。请告诉我如何实现这一目标。

表有4列，分别为C1，C2，C3，no_of_days和数据，如下所示。

C1|C2|C3|no_of_days
--------------------
A |B |C |7
X |B |C |8
Z |D |E |15
Y |D |E |22
P |D |E |34
Q |R |S |8

我需要以下面的格式显示数据

C2|C3|<=7D|8-14D|15-21D|22-27D
------------------------------
B |C |1   |1    |0     |0
D |E |0   |1    |1     |1
R |S |0   |1    |0     |0

Answer 1

您按C2和C3进行分组并总结事件：

select c2, c3
  , sum( case when no_of_days <= 7 then 1 else 0 end) as dlt8
  , sum( case when no_of_days between 8 and 14 then 1 else 0 end) as d8to14
  , sum( case when no_of_days between 15 and 21 then 1 else 0 end) as d15to21
  , sum( case when no_of_days between 22 and 27 then 1 else 0 end) as d22to27
from mytable
group by c2, c3
order by c2, c3;