我怎样才能在sql中多次计数？

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PLZ不介意

Answer 1

我认为你正在寻找这个：

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

Answer 2

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

如果我们正确地理解你，你想得到成本和scost的总和吗？

同样在SQL中，你的名字中不能有空格：如果你必须使用空格，拼盘顺序应该是拼盘顺序或[拼盘顺序]。