如果在intebase的group by子句中不支持大小写，那么如何按案例的结果进行分组

Question

我尝试过使用列别名，列号，使用组中的case语句，没有运气。这是interbase的缺点吗？

select case when vp.preferredvendor = 'Y' then vp.name else 'Misc' end as vendor, sum(sa.totalfare) from SalesActivity(1,1,2, '2014-01-01', '2014-02-01') sa join booking bk on bk.bookingno = sa.bookingno join profile vp on bk.vendor_linkno = vp.profileno group by vendor

Answer 1

重复case：

select (case when vp.preferredvendor = 'Y' then vp.name
             else 'Misc'
        end) as vendor,
       sum(sa.totalfare)
from SalesActivity(1,1,2, '2014-01-01', '2014-02-01') sa join
     booking bk
     on bk.bookingno = sa.bookingno join
     profile vp
     on bk.vendor_linkno = vp.profileno
group by (case when vp.preferredvendor = 'Y' then vp.name
               else 'Misc'
          end);

作为旁注，一些数据库确实允许在group by子句中使用列别名，但绝对不是所有这些都是标准所必需的。

Answer 2

我对Interbase不熟悉，但考虑到你尝试过的失败，下一步就是尝试子查询：

select vendor, sum(totalfare)
from (
   select
     case
       when vp.preferredvendor = 'Y' then vp.name
       else 'Misc'
     end as vendor,
     sa.totalfare
   from
     SalesActivity(1,1,2, '2014-01-01', '2014-02-01') sa
   join
     booking bk on bk.bookingno = sa.bookingno
   join
     profile vp on bk.vendor_linkno = vp.profileno)
group by vendor