Question

我在MS Access中有表格，其中包含年份，期间（仅1和2的值），Costs_Per_Capita和CALCULATED_Period_Avg_Costs，PK是ID。

我需要计算CALCULATED_Period_Avg_Costs。它应该从Costs_Per_Capita列返回指定时间段内Period的平均值。在Excel中，我使用SUMIF / COUNTIF执行此操作，返回平均IF。

您是否有一些建议如何在SQL中编写代码来执行此操作？

结果应该如下：

Costs_Per_Capita    Period              CALCULATED_Period_Avg_Costs
15,505              1                   15976.27582
16,368              1                   15976.27582
16,037              1                   15976.27582
15,995              1                   15976.27582
15,000              2                   16000
17,000              2                   16000

我用过声明：

SELECT 
Costs_Per_Capita, Period
IFF (Period = 1, 
(Select AVG(Costs_Per_Capita) From Costs Where Period = 1), 
(Select AVG(Costs_Per_Capita) From Costs Where Period = 2) 
AS result
FROM Costs;

在查询表达式中仍然出现“语法错误（缺少运算符）......”

Answer 1

我想我知道你要求的是什么，我相信这就是你要找的东西 -

Select
    Costs_Per_Capita,
    Related_Period_ID,
    (Select 
        Case when Related_Period_ID = 1 then 
        (Select
            AVG(Costs_Per_Capita)
            From Costs_Per_Capita_Table
            Where Related_Period_ID = 1)
        else 
       (Select
            AVG(Costs_Per_Capita)
            From Costs_Per_Capita_Table
            Where Related_Period_ID = 2)
        END 
    )
    From
    Costs_Per_Capita_Table

将CASE更改为IFF

Select 
        IFF (Related_Period_ID = 1, 
        (Select
            AVG(Costs_Per_Capita)
            From Costs_Per_Capita_Table
            Where Related_Period_ID = 1),
       (Select
            AVG(Costs_Per_Capita)
            From Costs_Per_Capita_Table
            Where Related_Period_ID = 2)

Answer 2

我这样做： SELECT Costs.Costs_Per_Capita，Costs.Period，

IIF（Costs.Period = 1，

（从期间= 1的成本中选择AVG（Costs_Per_Capita）），

（从期间= 2的成本中选择AVG（Costs_Per_Capita））

AS结果

FROM Costs;

其他方式，如果更多句点apper正在使用子查询，那就更好了：

SELECT Costs.Period，Costs.Costs_Per_Capita，tmpQry.CALCULATED_Period_Avg_Costs

FROM OF INES JOIN（SELECT Costs.Period，Avg（Costs.Costs_Per_Capita）

AS CALCULATED_Period_Avg_Costs FROM Costs

GROUP BY Costs.Period）AS tmpQry ON Costs.Period = tmpQry.Period;

也许有人会在以后使用它...

Answer 3

Select CostsPerCapital, Period, avg(CostPerCapita) over (partition by Period)
From Table
Where....
Order by ...

如何在SQL中获得Average IF语句？

3 个答案: