How to get the first row values in sql server query - sql

Question

My requirement is AllowedAmount for any latest postdate with latest PaymentID.I have tried many times just to get the firstrow value .But i get 2 rows instead.I tried using rownumber() but its not applicable after selecting for all patient name it doesn't give correct output .Does any one has another method apart from top 1 and rownumber() partition.
My requirement is get One ChargeID with AllowedAmount for the latest Postdate with latest PaymentID
SELECT
DISTINCT
TM.[PatientName] AS [PATIENT NAME],
[dbo].[SplitString](TM.InsPlanName, '(') AS [ Insurance],
ISNULL(TMmm1.ChargeAmount, 0) AS [Amount Billed],
ISNULL(TMM1.AllowedAmount, 0) AS AllowedAmount,
TMM1.PostDate,
TMM1.PaymentID,
TM.ChargeID AS ChargeID
FROM [MasterReport] AS TM
LEFT OUTER JOIN (SELECT
SUM(ISNULL(ChargeAmount, 0)) AS ChargeAmount,
[ChargeID]
FROM [dbo].[TransactionMasterReport]
WHERE transactiontype = 'Charges'
GROUP BY [ChargeID]) AS TMmm1
ON TM.ChargeID = TMmm1.ChargeID
LEFT OUTER JOIN (SELECT DISTINCT
MAX(PostDate) AS PostDate,
MAX(ISNULL(PaymentID, 0)) AS PaymentID,
[ChargeID],
AllowedAmount
FROM [dbo].[TransactionMasterReport]
WHERE ([TransactionType] = 'Payments'
OR [TransactionType] = 'Adjustments')
AND AllowedAmount >= 1
AND PaymentSource LIKE '%Primary%'
GROUP BY [ChargeID],
PostDate,
AllowedAmount,
PaymentID) AS TMM1
ON TM.[ChargeID] = TMM1.[ChargeID]
WHERE TM.ChargeId = 4255
ORDER BY TM.[ChargeID]
When I use top 1 in left outer join I get 0.00 in allowed Amount which is incorrect .

Answer 1

This should work, after you play with it for syntax errors. I do not have tables nor data that match yours. The changes are in the second LeftJoin to use Row_Number ordered by Descending of your fields. You may need to enclose the whole thing in another Select (...) and move the Where RN1 = 1 below that.
SELECT
DISTINCT
TM.[PatientName] AS [PATIENT NAME],
[dbo].[SplitString](TM.InsPlanName, '(') AS [ Insurance],
ISNULL(TMmm1.ChargeAmount, 0) AS [Amount Billed],
ISNULL(TMM1.AllowedAmount, 0) AS AllowedAmount,
TMM1.PostDate,
TMM1.PaymentID,
TM.ChargeID AS ChargeID
FROM [MasterReport] AS TM
LEFT OUTER JOIN (SELECT
SUM(ISNULL(ChargeAmount, 0)) AS ChargeAmount,
[ChargeID]
FROM [dbo].[TransactionMasterReport]
WHERE transactiontype = 'Charges'
GROUP BY [ChargeID]) AS TMmm1
ON TM.ChargeID = TMmm1.ChargeID
LEFT OUTER JOIN (SELECT
PostDate,
ISNULL(PaymentID, 0) AS PaymentID,
ChargeID,
AllowedAmount,
Row_Number() Over(Partition By ChargeID Order By PostDate Desc, PaymentID Desc) as RN1
FROM [dbo].[TransactionMasterReport]
WHERE ([TransactionType] = 'Payments'
OR [TransactionType] = 'Adjustments')
AND AllowedAmount >= 1
AND PaymentSource LIKE '%Primary%'
) AS TMM1
ON TM.[ChargeID] = TMM1.[ChargeID]
WHERE RN1 = 1
and TM.ChargeId = 4255
ORDER BY TM.[ChargeID]

Answer 2

We don't know the actual scenario but as suggested above it should work but as you said it's again returning the same output so use query as a subquery as below and try
To return only one record from the whole output
SELECT TOP 1 *
FROM ( <your query> )
ORDER BY postdate, paymentid DESC
To return top 1 value of each ChargeID
SELECT TOP (1) WITH TIES *
FROM ( <your query> )
GROUP BY ChargeID
ORDER BY postdate, paymentid DESC

Answer 3

I think, you should change your query like,
SELECT TOP 1 <your fields>
FROM [MasterReport] AS TM
LEFT OUTER JOIN <TMmm1> ON TM.ChargeID = TMmm1.ChargeID
LEFT OUTER JOIN <TMM1> ON TM.[ChargeID] = TMM1.[ChargeID]
WHERE TM.ChargeId = 4255
ORDER BY TMM1.PostDate DESC, TMM1.PaymentID DESC
It will give you only one row(TOP 1) and it will be the latest PostDate & PaymentID