从2个SQL查询计算

Question

我有两个问题，我不知道如何做一个简单的数学运算。

SELECT count(*) FROM CUSTOMERINFO
where member between '2013-01-01' and '2013-12-31' 

返回：7823

select COUNT(DISTINCT ORDERINFO.OrderID) from orderinfo, orderiteminfo 
where code = '810samp' 
AND ORDERINFO.OrderID = ORDERITEMINFO.OrderID
AND orderinfo.PrepareDate between '2013-01-01' and '2013-12-31' 

返回：4106

我需要返回查询：4106/7823 X 100

Answer 1

没有经过测试的代码，但这应该适合你：

SELECT (SELECT count(*) FROM CUSTOMERINFO
where member between '2013-01-01' and '2013-12-31') / 
(select COUNT(DISTINCT ORDERINFO.OrderID) from orderinfo, orderiteminfo 
where code = '810samp' 
AND ORDERINFO.OrderID = ORDERITEMINFO.OrderID
AND orderinfo.PrepareDate between '2013-01-01' and '2013-12-31')
* 100 

Alternate将是

DECLARE @int1 as int
DECLARE @int2 as int
SET @int1 = (SELECT count(*) FROM CUSTOMERINFO
    where member between '2013-01-01' and '2013-12-31')
SET @int2 = (select COUNT(DISTINCT ORDERINFO.OrderID) from orderinfo, orderiteminfo 
    where code = '810samp' 
    AND ORDERINFO.OrderID = ORDERITEMINFO.OrderID
    AND orderinfo.PrepareDate between '2013-01-01' and '2013-12-31')
SELECT @int1/@int2 X 100

Answer 2

只需使用以下语法：

SELECT (
  CAST((<your first query>) as decimal)
  /(<your second query>)
  * 100
  ) AS Percents;

所以你的查询应该是

SELECT (
  CAST((select COUNT(DISTINCT ORDERINFO.OrderID) from orderinfo, orderiteminfo 
        where code = '810samp' 
        AND ORDERINFO.OrderID = ORDERITEMINFO.OrderID
        AND orderinfo.PrepareDate between '2013-01-01' and '2013-12-31') as decimal)
  /(SELECT count(*) FROM CUSTOMERINFO
    where member between '2013-01-01' and '2013-12-31')
  * 100
  ) AS Percents;

请参阅this SQLFiddle