我无法在SQL代码中计算除法

Question

以下代码没有问题:

select donem, mekankodu, count(yayin_kodu) yc, 
       SUM(CASE WHEN iade =0 THEN 1 ELSE 0 END) yys
from 
(    select donem,
            bayi_adi,
            bayi_kodu,
            x.mekankodu,
            mekan_adi,
            mekan_tipi,
            yayin_kodu,
            yayin_adi,
            sum(x.b2b_dagitim + x.b2b_transfer) sevk,
            sum(x.b2b_iade) iade,
            sum(x.b2b_dagitim + x.b2b_transfer - x.b2b_iade) satis
    from mps_view2 x
    where x.donem = '200910'
    and x.yayin_kodu in (93,95,98,99,103,174,307,309,311,489,491,495,533,534,538,605,641,642,650,2539,
                         2697,4560,5049,5772,5950,5980,7318,7440,8086,8524,11161,12707,12708,12709,14376,
                         15107,15309,15633)
    and x.mekankodu in (31851,38569,7123,7403,7481)
    group by donem, bayi_adi, bayi_kodu, mekankodu, mekan_adi, mekan_tipi, yayin_kodu, yayin_adi
    order by donem, bayi_kodu, mekan_adi, yayin_adi
)
group by donem, mekankodu

当我想要包含yc/yss在我的结果表中时,我SELECT按如下方式安排部分:

select donem, mekankodu, count(yayin_kodu) yc, 
       SUM(CASE WHEN iade =0 THEN 1 ELSE 0 END) yys,
       yc/yys yo

但它给了

ORA-00904错误:YYS:标识符无效.

我该怎么办？

Answer 1

使用with语句:

with subquery_name as
(
    select
       donem,
       mekankodu,
       count(yayin_kodu) as yc, 
       SUM(CASE WHEN iade =0 THEN 1 ELSE 0 END) as yys
    from
        ...
)
select
    donem,
    mekankodu,
    yc,
    yys,
    yc/yys as yo
from
    subquery_name

这是PL/SQL的一个非常有用的功能.您正尝试在同一查询中访问生成的列,这是不可能的.使用with语句将允许您根据您在此处执行的其他计算列计算新列.