sql - 如何在sql中乘以计数？

Question

我尝试使用以下查询

Select cost + scost from
(Select count(order no) as cost 
From platter order where cost= cost*25*discountpercent) ,
(Select count(order no)as scost from schoolorder
Where scost=scost*25);

我正在学习 SQL，所以请不要介意

Answer 1

这是一种方法：

Create table #temp (cost as decimal(1,2), scost as decimal(1,2))

INSERT INTO #temp
(Select count(order no) as cost From platter order where cost= cost*25*discountpercent) ,
(Select count(order no)as scost from schoolorder
Where scost=scost*25);

Select cost + scost from #temp

如果我们对您的理解正确，您想获得成本和成本的总和吗？

同样在 SQL 中，您的名称中不能有空格：如果必须使用空格，则拼盘顺序应为拼盘顺序或 [拼盘顺序]。

Answer 2

我想你正在寻找这个：

SELECT
   (cost + scost) as Total_Cost,
   ((cost + scost) * 25 * discountpercent) as Discounted_Cost,
   count(order_number) as Order_Count
FROM
   schoolorder
WHERE
   scost = scost * 25