select case statement add information

Question

我有2個表cardinfo和paytb。在我的發言中，我通過CONT_ID加入了他們。

select (case when age_years >= 18 and age_years < 30 then '18-29' 
      when age_years < 50 then '30-49' 
      when age_years < 70 then '50-69' 
      when age_years < 100 then '70-100' 
      end) as age_range, 
      count(DISTINCT c.CONT_ID) as num, 
    CASE WHEN GENDER = '1' THEN 1 ELSE 0 END/COUNT(DISTINCT c.CONT_ID), 
    SUM(ACAUREQ_AUREQ_TX_DT_TTLAMT)/COUNT(*) 'TOTAL-Amount Avg' 
     from cardinfo c 
     left join paytb t 
      on c.CONT_ID = t.CONT_ID 
     group by (case when age_years >= 18 and age_years < 30 then '18-29' 
     when age_years < 50 then '30-49' 
     when age_years < 70 then '50-69' 
     when age_years < 100 then '70-100' 
     end) 
     order by min(age_years);  

現在，這示出了第一列2：

AGE_RANGE   NUM  GENDER  
---------+---------+---------------- 
18-29    828  50%   
30-49    2510  ??   
50-69    2014  ??   
70-100    649     

我要添加性別參數（0或1）從表中。然而，這是不工作：

CASE WHEN GENDER = '1' THEN 1 ELSE 0 END/COUNT(DISTINCT c.CONT_ID) 

SQLCODE = -122

而且我tryed找到交易的平均：

SUM(ACAUREQ_AUREQ_TX_DT_TTLAMT)/COUNT(*) 'TOTAL-Amount Avg' 

不幸的是這會給我一個DECFLOAT錯誤。
總和看起來是這樣的：

SUM(ACAUREQ_AUREQ_TX_DT_TTLAMT) 
    -----+---------+---------+---------+ 
    +1.232071426000000000000000E+0007 
    +3.062581021000000000000000E+0007 
    +2.399951792000000000000000E+0007 
    +8.228919170000000000000000E+0006 

Answer 1

我包裝了原始查詢了在派生表，以節省一些打字：

select age_range, 
     count(DISTINCT CONT_ID) as num, 
     CASE WHEN GENDER = '1' THEN 1 ELSE 0 END/COUNT(DISTINCT c.CONT_ID), 
     SUM(ACAUREQ_AUREQ_TX_DT_TTLAMT)/COUNT(*) 'TOTAL-Amount Avg' 
from 
(
    select (case when age_years >= 18 and age_years < 30 then '18-29' 
       when age_years < 50 then '30-49' 
       when age_years < 70 then '50-69' 
       when age_years < 100 then '70-100' 
      end) as age_range, 
      c.CONT_ID, 
      GENDER, 
      ACAUREQ_AUREQ_TX_DT_TTLAMT 
    from CARDUSR.CLIENT_INFO c 
    left join cardusr.sppaytb t 
     on c.CONT_ID = t.CONT_ID 
) 
group by age_range, GENDER 

Answer 2

您需要可以包括在group bygender或使其成爲參數聚合函數：

SUM(CASE WHEN GENDER = '1' THEN 1 ELSE 0 END)/COUNT(DISTINCT c.CONT_ID) 

然而，你可能並不需要COUNT(DISTINCT)。如果沒有必要，您可以簡化這：

AVG(CASE WHEN GENDER = '1' THEN 1.0 ELSE 0 END)