原始回复：
如果您已经知道需要哪些功能，那么我能想到的一种方法是，为您要在每个表中应用的每个方法/操作创建一个内联函数。我的意思是什么？例如，您在选择时提到了 FROM Customer_Detail 表，您可能需要一种方法“衍生（金额，日期）”。假设您可能需要的第二种方法（我只是弥补解释）是“derivative1（Amount1，Date1）”。我们创建了两个内联函数，每个函数都将在函数内部对预期列进行自己的计算，并按原样返回剩余的列。这样，您就可以从表中获取所有列，并将自定义计算作为基于集合的操作而不是标量操作执行。稍后，如果有意义，您可以在同一函数中组合列的独立计算。如果需要，您仍然可以使用这所有函数并执行 JOIN 以在单个集合中获取所有自定义计算，因为所有函数都将具有公共/未处理的列。请参见下面的示例。
IF object_id('Product','u') IS NOT NULL
DROP TABLE Product
GO
CREATE TABLE Product
(
pname sysname NOT NULL
,pid INT NOT NULL
,totalqty INT NOT NULL DEFAULT 1
,uprice NUMERIC(28,10) NOT NULL DEFAULT 0
)
GO
INSERT INTO Product( pname, pid, totalqty, uprice )
SELECT 'pen',1,100,1.2
UNION ALL SELECT 'book',2,300,10.00
UNION ALL SELECT 'lock',3,500,15.00
GO
IF object_id('ufn_Product_totalValue','IF') IS NOT NULL
DROP FUNCTION ufn_Product_totalValue
GO
CREATE FUNCTION ufn_Product_totalValue
(
@newqty int
,@newuprice numeric(28,10)
)
RETURNS TABLE AS
RETURN
(
SELECT pname,pid,totalqty,uprice,totalqty*uprice AS totalValue
FROM
(
SELECT
pname
,pid
,totalqty+@newqty AS totalqty
,uprice+@newuprice AS uprice
FROM Product
)qry
)
GO
IF object_id('ufn_Product_totalValuePct','IF') IS NOT NULL
DROP FUNCTION ufn_Product_totalValuePct
GO
CREATE FUNCTION ufn_Product_totalValuePct
(
@newqty int
,@newuprice numeric(28,10)
)
RETURNS TABLE AS
RETURN
(
SELECT pname,pid,totalqty,uprice,totalqty*uprice/100 AS totalValuePct
FROM
(
SELECT
pname
,pid
,totalqty+@newqty AS totalqty
,uprice+@newuprice AS uprice
FROM Product
)qry
)
GO
SELECT * FROM ufn_Product_totalValue(10,5)
SELECT * FROM ufn_Product_totalValuepct(10,5)
select tv.pname,tv.pid,tv.totalValue,pct.totalValuePct
from ufn_Product_totalValue(10,5) tv
join ufn_Product_totalValuePct(10,5) pct
on tv.pid=pct.pid
还要检查输出，如下所示。
编辑2：
三点平滑算法
IF OBJECT_ID('Test3PointSmoothingAlgo','u') IS NOT NULL
DROP TABLE Test3PointSmoothingAlgo
GO
CREATE TABLE Test3PointSmoothingAlgo
(
qty INT NOT NULL
,id INT IDENTITY NOT NULL
)
GO
INSERT Test3PointSmoothingAlgo( qty ) SELECT 10 UNION SELECT 20 UNION SELECT 30
GO
IF object_id('ufn_Test3PointSmoothingAlgo_qty','IF') IS NOT NULL
DROP FUNCTION ufn_Test3PointSmoothingAlgo_qty
GO
CREATE FUNCTION ufn_Test3PointSmoothingAlgo_qty
(
@ID INT --this is a dummy parameter
)
RETURNS TABLE AS
RETURN
(
WITH CTE_3PSA(SmoothingPoint,Coefficients)
AS --finding the ID of adjacent points
(
SELECT id,id
FROM Test3PointSmoothingAlgo
UNION
SELECT id,id-1
FROM Test3PointSmoothingAlgo
UNION
SELECT id,id+1
FROM Test3PointSmoothingAlgo
)
--Apply 3 point Smoothing algorithms formula
SELECT a.SmoothingPoint,SUM(ISNULL(b.qty,0))/3 AS Qty_Smoothed--this is a using 3 point smoothing algoritham formula
FROM CTE_3PSA a
LEFT JOIN Test3PointSmoothingAlgo b
ON a.Coefficients=b.id
GROUP BY a.SmoothingPoint
)
GO
SELECT SmoothingPoint,Qty_Smoothed FROM dbo.ufn_Test3PointSmoothingAlgo_qty(NULL)
