MS SQL 中的通货膨胀计算

Question

我有以下要求要满足。 如何简单地实现这一点。

有一个通货膨胀率表如下

2009, 5%
2010, 5%
2011, 5%
2012, 5%
2013, 5%

我需要先得到

2009, 5%, 5
2010, 5%, 5.25        - which is 5% over 5
2011, 5%, 5.5125      - which is 5% over 5.25
2012, 5%, 5.788125    - which is 5% over 5.5125
2013, 5%, 6.07753125  - which is 5% over 5.788125

然后得到

2009, 5%, 5          , 5
2010, 5%, 5.25       , 10.25            = 5.25 + 5
2011, 5%, 5.5125     , 15.7625          = 5.5125 + 10.25 and so on
2012, 5%, 5.788125   , 21.550625
2013, 5%, 6.07753125 , 27.62815625

Answer 1

我认为在 SQLserver 上执行此操作的最佳方法是使用带有递归的公共表表达式。 我不是 100% 确定，因为我不能在这里测试它，但是像下面的例子一样。 顺便说一句，我假设表中的比率存储为分数，所以 5% 是 1.05，10.25% 是 1.1025 等等。

WITH MyCompoundRates (TheYear, TheRate, CompoundRate)
AS
(
-- select one anchor record, starting point record
    SELECT
        TheYear,
        TheRate, -- I'm assuming "5%" is stored as value 1.05
        TheRate as CompoundRate
    FROM
        MyRatesTable
    WHERE
        TheYear = 2009 -- <- starting point for recursion
    UNION ALL
-- select recursive records, by linking them to a previous record
    SELECT
        r.TheYear,
        r.TheRate,
        r.TheRate * c.CompoundRate as CompoundRate -- calculate compound rate
    FROM
        MyRatesTable r
        JOIN MyCompoundRates c ON r.TheYear = c.TheYear+1 -- recursion! link a year to previous year
)
-- Statement that executes the CTE
SELECT
        TheYear,
        TheRate,
        CompoundRate
FROM
    MyCompoundRates

Answer 2

缺少PRODUCT()语句，查询变得比其他情况下所需的复杂一些，但这应该可以很好地工作； 它对每个步骤使用通用表表达式，并使用对数和来模拟PRODUCT() 。

WITH cte1 AS (
  SELECT a.year, 5 * EXP(SUM(COALESCE(LOG(b.rate),0))) rate
  FROM inflation a LEFT JOIN inflation b ON a.year > b.year
  GROUP BY a.year
), cte2 AS (
  SELECT year, rate, SUM(rate) OVER (ORDER BY year) rate_sum FROM cte1
)
SELECT * FROM cte2 ORDER BY year

一个用于测试的 SQLfiddle 。

Answer 3

您可以为此SQL Fiddle使用递归 CTE。

WITH    RecursiveCTE
AS      (
        SELECT TOP 1 [Year], 
                     [Inflation], 
                     CAST(1 AS numeric(38,37)) AS Compound, 
                     CAST(5 AS numeric(38,37)) AS Value, CAST(5 AS numeric(38,10)) AS Total
        FROM Rates
        ORDER BY [Year]
        UNION   ALL
        SELECT  R.[Year], R.[Inflation], R.Compound, R.Value, R.Total
        FROM    (
                SELECT  T.*,
                         CAST(1 + R.[Inflation] * Compound AS numeric(38,37)) AS Compound,  
                         CAST(R.Value * (1 + T.Inflation) AS numeric(38,37)) AS Value,
                         CAST(R.Value * (1 + T.Inflation) AS numeric(38,37)) + R.Total AS Total,
                        rn = ROW_NUMBER() OVER (ORDER BY T.[Year])
                FROM    Rates T
                JOIN    RecursiveCTE R
                        ON  R.[Year] < T.[Year]
                ) R
        WHERE   R.rn = 1
        )
SELECT  [Year], [Inflation], Value, Total
FROM    RecursiveCTE;

Answer 4

我认为每个人都玩得很开心，因为同时出现了一堆答案。

DECLARE @Inflation TABLE (
    YearNum INT
    ,Inflation FLOAT
    ,LowerCalc INT
    ,AdjustedInflation FLOAT
    ,CumulativeAdjustment FLOAT);

INSERT INTO @Inflation
SELECT T.YearNum, T.Inflation, T.YearNum, T.Inflation, T.Inflation
FROM (VALUES
    (2009, 0.05),
    (2010, 0.05),
    (2011, 0.05),
    (2012, 0.05),
    (2013, 0.05)) T (YearNum, Inflation)

DECLARE @LoopBit BIT = 1;

WHILE @LoopBit = 1
BEGIN
    UPDATE I SET
        LowerCalc = IG.YearNum
        ,AdjustedInflation = I.AdjustedInflation * (1.0 + IG.Inflation)
        ,CumulativeAdjustment = I.CumulativeAdjustment + (I.AdjustedInflation * (1.0 + IG.Inflation))
    FROM @Inflation I
    LEFT JOIN @Inflation IG ON IG.YearNum = I.LowerCalc - 1
    WHERE I.LowerCalc > (SELECT MIN(YearNum) FROM @Inflation)

    IF @@ROWCOUNT = 0 SET @LoopBit = 0
END

SELECT *
FROM @Inflation

Answer 5

如果我们有一个表 Inflation (Yr INT, Rate float) ，我们可以得到累积的通货膨胀如下：

select i1.yr, i1.rate,  EXP(SUM(LOG(1+i2.rate))) -1 AccRate
from inflation I1
inner join inflation I2 on i1.yr >=i2.yr
group by i1.yr, i1.rate
order by 1,2 

见http://sqlfiddle.com/#!6/508b5/1/0

Answer 6

如果通货膨胀率每次都与您的示例中所示相同，则以下公式将有所帮助，无需复杂的查询！：

declare @P float=5;
declare @r float =0.05;--rate = 5/100
declare @n float =1;-- 1 since compounded yearly
declare @t float = 4;--For 4 years

select @P* POWER ( (1+@r/@n),(@n*@t));
--result = 6.07753125

Answer 7

我想你可以在这里使用我们在学校学到的通货膨胀概念。

案例 1 - 当通货膨胀每年给出时 --（不是累积的并且全年都是一样的）。

看起来就像这里的情况一样。

所以你可以只使用公式。

Inflation at any given year=Inflation(in Year1)*(1+inflation(in year1)/100)^(n-1)

另外我相信你会在计算中的某个地方使用这种通货膨胀。

这是给你的代码

select 5*power((1+(5/cast(100 as float))),n);
Year1=select 5*power((1+(5/cast(100 as float))),1);--5
Year1=select 5*power((1+(5/cast(100 as float))),2);--5.5125
Year1=select 5*power((1+(5/cast(100 as float))),3);--5.788125
Year1=select 5*power((1+(5/cast(100 as float))),4);--6.07753125
Year1=select 5*power((1+(5/cast(100 as float))),5);--6.3814078125
Year1=select 5*power((1+(5/cast(100 as float))),6);--6.700478203125

你只需要声明一个变量n。