ขออนุญาตสอบถามเรื่อง Query Sql ในการเอา Alias มาใช้งานหน่อยครับ

 Select a.RequestID,b.FullName,a.RequestDate,(select DATEname(M,RequestDate) ) as SearchMonth
   	,c.ErrorName,concat(substring( a.RequestRemark,0,50),'...' ) as SubRemark,SubStatus = Case  a.RequestStatus
     when 'Open' then 'รอดำเนินการ' 
     When 'Closed' then 'เสร็จเรียบร้อย' 
   End 
From RtbRequest  a 
	Left outer join tbLogin b 
 On a.RequestEmpID = b.id
Left outer join RtbError c
On a.RequestErrorID = C.ErrorID 
 Where 
(select DATEname(M,RequestDate) )= 'January' 
order by a.requestID DESC 

select * from (
Select a.RequestID,b.FullName,a.RequestDate,(select DATEname(M,RequestDate) ) as SearchMonth
   	,c.ErrorName,concat(substring( a.RequestRemark,0,50),'...' ) as SubRemark,SubStatus = Case  a.RequestStatus
     when 'Open' then 'รอดำเนินการ' 
     When 'Closed' then 'เสร็จเรียบร้อย' 
   End 
From RtbRequest  a 
	Left outer join tbLogin b 
 On a.RequestEmpID = b.id
Left outer join RtbError c
On a.RequestErrorID = C.ErrorID
) t1
Where SearchMonth= 'January' order by requestID DESC

SELECT Fuck.*, tmp69.*, ISNULL(FuckAgain.Status, 'นมบูดนมเน่า') AS ASS
FROM RtbRequest Fuck
OUTER APPLY
(
 SELECT TOP 1 DATENAME(M, GETDATE()), DATENAME(M, DATEADD(M, 1, GETDATE()))
 FROM RtbRequest tmp96
 WHERE Fuck.RequestEmpID = tmp96.RequestEmpID
) tmp69
        (FuckAliasMomColumn1, FuckAliasMomColumn2
        )  
LEFT JOIN RtbRequest FuckAgain ON Fuck.RequestEmpID  = FuckAgain.RequestEmpID             
WHERE FuckAliasMomColumn1 = 'May'

USE tempdb
GO

DECLARE @LoanAmount NUMERIC(10, 2) = 10000 --ยอดเงินกู้ 
DECLARE @AnnualRate NUMERIC(10, 8) = 6.8 --อัตราดอกเบี้ย/ปี
DECLARE @NumberOfMonths INT = 48 -- four year
DECLARE @StartDate DATETIME = '2013-12-01';

--Principle, Capital = เงินต้น
--Interest = ดอกเบี้ย
--Compound interest = ดอกเบี้ยทบต้น

WITH InputVariables
AS (
	SELECT P, M, R,	C = ROUND((P * R) / (1 - POWER(1 + R, - M)), 2)
	FROM (
		SELECT P = @LoanAmount,	M = @NumberOfMonths, R = @AnnualRate / 12 / 100
		) InputData
	),
MonthlyPayments (
	PmtNo,
	PmtDate,
	Balance,
	Principle,
	Interest,
	CumulPrinciple,
	CumulInterest
	)
AS (
	SELECT X, 
	    @StartDate,
		--DATEADD(MONTH, DATEDIFF(MONTH, '19000101', @StartDate), '19000101'),
		CAST(NewBalance AS NUMERIC(10, 2)),
		CAST(P - NewBalance AS NUMERIC(10, 2)),
		CAST(C - (P - NewBalance) AS NUMERIC(10, 2)),
		CAST(P - NewBalance AS NUMERIC(10, 2)),
		CAST(C - (P - NewBalance) AS NUMERIC(10, 2))
	FROM InputVariables
	CROSS APPLY (
		SELECT X = 1
		) CalcPmtNo
	CROSS APPLY (
		SELECT NewBalance = ROUND(P * POWER(1 + R, X) - (POWER(1 + R, X) - 1) * C / R, 2)
		) CalcNewBalance
	
	UNION ALL
	
	SELECT X,
		DATEADD(MONTH, 1, mp.PmtDate),
		CAST(NewBalance AS NUMERIC(10, 2)),
		CAST(mp.Balance - NewBalance AS NUMERIC(10, 2)),
		CAST(C - (mp.Balance - NewBalance) AS NUMERIC(10, 2)),
		CAST(mp.CumulPrinciple + mp.Balance - NewBalance AS NUMERIC(10, 2)),
		CAST(mp.CumulInterest + C - (mp.Balance - NewBalance) AS NUMERIC(10, 2))
	FROM MonthlyPayments mp
	CROSS JOIN InputVariables
	CROSS APPLY (
		SELECT X = mp.PmtNo + 1
		) CalcPmtNo
	CROSS APPLY (
		SELECT NewBalance = CASE 
				WHEN X = M
					THEN 0.00 /* Last Payment */
				ELSE 
				    ROUND(P * POWER(1 + R, X) - (POWER(1 + R, X) - 1) * C / R, 2)
				END
		) CalcNewBalance
	WHERE X <= M
	)
SELECT PmtNo,
	PmtMonth = DATENAME(MONTH, PmtDate) + STR(YEAR(PmtDate), 5),
	PmtAmount = Principle + Interest,
	Principle,
	Interest,
	CumulPrinciple,
	CumulInterest,
	Balance
FROM MonthlyPayments
ORDER BY PmtNo
OPTION (MAXRECURSION 32767);

DECLARE @table TABLE
                    (
                     entrydate DATETIME, openingbal DECIMAL(15, 4), credit DECIMAL(15, 4), debit DECIMAL(15, 4), closingbal DECIMAL(15, 4)
                    );

INSERT INTO @table
       SELECT '2014-09-01 12:05:43.203', 0.000, 0.000, 1.000, 0.000
       UNION 
       SELECT '2014-09-01 13:05:43.203', 0.000, 1.000, 0.000, 0.000
       UNION 
       SELECT '2014-09-10 08:05:43.203', 0.000, 1.000, 0.000, 1.000
       UNION               
       SELECT '2014-10-02 23:05:43.203', 94000.000, 0.000, 900.000, 93100.000
       UNION
       SELECT '2014-10-03 23:05:43.203', 0.000, 1000.000, 0.000, 0.000
       UNION
       SELECT '2014-10-03 23:06:43.203', 0.000, 0.000, 500.000, 0.000
       UNION
       SELECT '2014-10-14 23:52:27.327', 4000.000, 0.000, 1500.000, 2500.000;
       
--DECLARE @TotalPrevBalance decimal(15,3)
--SET @TotalPrevBalance = (SELECT SUM(credit - debit) FROM @table  WHERE entrydate < '2014-10-01 23:05:43.203')
--UPDATE @table SET openingbal =  openingbal + @TotalPrevBalance WHERE entrydate = '2014-10-02 23:05:43.203'
UPDATE @table SET openingbal =  openingbal + 
                               (SELECT SUM(ISNULL(credit, 0.000) - ISNULL(debit, 0.000)) FROM @table  
                                WHERE entrydate < '2014-10-01 23:05:43.203') 
                                WHERE entrydate = '2014-10-02 23:05:43.203'
;WITH cte
     AS
        (SELECT *, ROW_NUMBER() OVER
                                    (ORDER BY entrydate Asc
                                    ) rid
         FROM @table WHERE entrydate >= '2014-10-01 23:05:43.203'
        ),
     cte1
     AS
        (
     SELECT entrydate, openingbal , credit, debit, CAST(openingbal + credit - debit AS DECIMAL(15, 4)
                                                      ) AS closingbal, rid
     FROM cte WHERE rid = 1    
     UNION ALL    
     SELECT curr.entrydate, CAST(curr.openingbal + prev.closingbal AS DECIMAL(15, 4)
                                ), curr.credit, curr.debit, CAST(curr.openingbal + prev.closingbal + curr.credit - curr.debit AS DECIMAL(15, 4)
                                                                ) AS closingbal, curr.rid
     FROM cte curr INNER JOIN cte1 prev ON curr.rid = prev.rid + 1
        )
        
     SELECT *
     FROM cte1
     ORDER BY entrydate;
     
     
--2014-10-02 23:05:43.203	94001.000	0.000	900.000	93101.000	1
--2014-10-03 23:05:43.203	93101.000	1000.000	0.000	94101.000	2
--2014-10-03 23:06:43.203	94101.000	0.000	500.000	93601.000	3
--2014-10-14 23:52:27.327	97601.000	0.000	1500.000	96101.000	4

-- 97601 = 93601.000 + 4000