如何做SUM与案例

Question

当我使用以下查询时，结果显示为我想要的结果：

select (TARIF + TAMBAHAN - (case when (select NILAI from PROMOTRIP where KODETRIP = OD.KODETRIP and URUTAN = OD.URUTAN) is null then 0 else (select NILAI from PROMOTRIP where KODETRIP = OD.KODETRIP and URUTAN = OD.URUTAN) end)) from ORDERDETAIL OD where KODETRIP = 'TR201408060051' and TGLBATAL is null 

但是当我想添加它时，结果错误：

Answer 1

尝试将第一个查询合并为嵌套查询，并在外部查询上使用SUM。像这样：

SELECT SUM(*) FROM (YOUR_FIRST_QUERY)

Answer 2

这样做。

return view('errors.404', ['msg' => 'some message']);