Question

如果我运行此查询：

SELECT 
   [BBox]
  ,SUM(GrossPnL) AS 'Gross'
  ,SUM(SharesTraded) AS 'Shares'
  ,(SUM(GrossPnL)/SUM(SharesTraded)) AS 'CPS'
FROM [PrimusGroup].[dbo].[PrmsBlotter]
WHERE [RunType] = 'Backtesting'
GROUP BY [BBox]

对于有0股交易的情况，我得到0除错。

我试图解决这个问题：

SELECT 
   [BBox]
  ,SUM(GrossPnL) AS 'Gross'
  ,SUM(SharesTraded) AS 'Shares'
  ,(IF SUM(SharesTraded) > 0 
    (SUM(GrossPnL)/SUM(SharesTraded)) 
   ELSE 
     SUM(GrossPnL)) AS 'CPS'
FROM [PrimusGroup].[dbo].[PrmsBlotter]
WHERE [RunType] = 'Backtesting'
GROUP BY [BBox]

但是我在sum附近得到了不正确的语法。难道我做错了什么？

Answer 1

使用location.locationSchedule.scheduleType == 1表达式。

case

Answer 2

使用IIF：

 SELECT 
       [BBox]
      ,SUM(GrossPnL) AS 'Gross'
      ,SUM(SharesTraded) AS 'Shares'
      ,(IIF SUM(SharesTraded) > 0, 
        (SUM(GrossPnL)/SUM(SharesTraded)), 
         SUM(GrossPnL)) AS 'CPS'
    FROM [PrimusGroup].[dbo].[PrmsBlotter]
    WHERE [RunType] = 'Backtesting'
    GROUP BY [BBox]

Answer 3

您可以使用IIF

SELECT [BBox]
  ,SUM(GrossPnL) AS 'Gross'
  ,SUM(SharesTraded) AS 'Shares'
  ,IIF(SUM(SharesTraded) > 0, SUM(GrossPnL)/SUM(SharesTraded), SUM(GrossPnL)) AS 'CPS'
FROM [PrimusGroup].[dbo].[PrmsBlotter]
WHERE [RunType] = 'Backtesting'
GROUP BY [BBox]

Answer 4

如果'SharesTraded'= 0但是将0和1视为相同的值（你上面所做的）似乎是错误的，我看不出所需的输出是什么。

假设0是特殊情况，你的情况使用CASE WHEN情况并且只是使'ELSE'为NULL但我喜欢在可能的情况下使用'NULLIF'函数。

所以：

(SUM(GrossPnL)/SUM(SharesTraded)) AS 'CPS'

变为：

(SUM(GrossPnL)/NULLIF(SUM(SharesTraded),0)) AS 'CPS'

通过将SUM（SharesTraded）设置为0，当'SharesTraded'= 0时，这将导致'CPS'为NULL，从而解决错误。

不确定show-plan中的内容，但它有助于保持代码清晰简洁。

在Query中除以0错误

4 个答案: