从单列添加或派生两列

Question

给定以下数据框：

-

+------------------+--------------------+
|Customer_ID|Project_ID|QUESTION_TYP|ANSWER|
+---------+----------+-------------+---------+
   1            1         2nd QUES      YES
   1            1          2nd QUES     YES
   1            2          2nd QUES      NO 
   1            2          2nd Ques.     Yes

如何在上述数据框中再添加 2 列

块引用

比如 col_1 有 Yes 答案的计数，col_2 有 No 答案的计数。

 -+------------------+--------------------++--------------------+
|Customer_ID|Project_ID|QUESTION_TYP|ANSWER|col_1|col_2
+---------+----------+-------------+---------+------+-------------
   1            1         2nd QUES      YES.    2     0
   1            2          2nd QUES     NO      0.    1
   1            2          2nd Ques.    Yes     1.    0

请帮忙。我已经尝试了大多数解决方案，但我得到的结果是肯定的或否定的，但我需要按行排列。请帮助

Answer 1

这看起来像窗口函数。假设您希望通过customer_id 计数：

select t.*,
       sum(case when answer = 'YES' then 1 else 0 end) over (partition by customer_id) as col_1,
       sum(case when answer = 'NO' then 1 else 0 end) over (partition by customer_id) as col_2
from t;

或者，如果您想计算所有数据，只需将 (partition by customer_id) 替换为 ()。

注意：这会将计数放在两个列中。如果您只想要与该行答案匹配的列中的计数：

select t.*,
       (case when answer = 'YES'
             then sum(case when answer = 'YES' then 1 else 0 end) over (partition by customer_id)
             else 0
        end) as col_1,
       (case when answer = 'NO'
             then sum(case when answer = 'NO' then 1 else 0 end) over (partition by customer_id)
             else 0
        end) as col_2
from t;

但是，我认为两者兼有是有道理的。