How to select only unique values from this table based on criteria? - sql

Question

I want to select only the first record from each group. So basically I only want the data for first processing date column and don't want the rest of the date for each product.
My current code as below
SELECT
C.AccountID as ABN_ACC ,
C.ProductSymbol,
C.ProductShortName,
S.ReactorProduct AS REC_PROD,
C.CurrencyCode AS PROD_CCY,
C.CountryOfPayment AS PAYCONTRY,
C.DividendValueCur AS PAYCCY,
C.DividendValue AS DIV_AMNT,
CONCAT ((IIF (C.QuantitySettledNoTax_LS = 'S' ,(-1*C.QuantitySettledNoTax),C.QuantitySettledNoTax )),(IIF(C.QuantitySettledTax_LS = 'S',(-1*C.QuantitySettledTax),QuantitySettledTax))) AS DIVQTY ,
C.ExdividendDate AS EXDATE,
C.Recorddate AS RECDATE,
C.DividendPayDate AS PAYDATE
From "LiquidCDW". [Staging].[CA_CorporateActions] AS C
RIGHT JOIN "LiquidCDW".[Staging].[POS_SettledPositions] AS P ON C.Recorddate = P.ProcessingDate AND C.AccountID = p.AccountID AND C.ProductSymbol = P.ProductSymbol AND C.DividendValueCur = P.CurrencyCode
INNER JOIN "LiquidCDW".[Transformation].[Mapping_Product_ABNReactor] AS S ON C.ProductSymbol = S.ReactorProduct AND S.ValidTo IS NULL AND S.ProductType = 'E' AND c.DividendValueCur = S.Currency
where C.ExdividendDate >= '20210201'
ORDER by C.ProductSymbol , C.CurrencyCode

Answer 1

One approach uses ROW_NUMBER:
WITH cte AS (
SELECT
ROW_NUMBER() OVER (PARTITION BY C.ProductSymbol ORDER BY processingDate) rn,
C.AccountID AS ABN_ACC,
C.ProductSymbol,
C.ProductShortName,
S.ReactorProduct AS REC_PROD,
C.CurrencyCode AS PROD_CCY,
C.CountryOfPayment AS PAYCONTRY,
C.DividendValueCur AS PAYCCY,
C.DividendValue AS DIV_AMNT,
CONCAT((IIF(C.QuantitySettledNoTax_LS = 'S',
(-1*C.QuantitySettledNoTax), C.QuantitySettledNoTax)),
(IIF(C.QuantitySettledTax_LS = 'S',
(-1*C.QuantitySettledTax),QuantitySettledTax))) AS DIVQTY,
C.ExdividendDate AS EXDATE,
C.Recorddate AS RECDATE,
C.DividendPayDate AS PAYDATE
FROM [LiquidCDW].[Staging].[CA_CorporateActions] AS C
RIGHT JOIN "LiquidCDW".[Staging].[POS_SettledPositions] AS P
ON C.Recorddate = P.ProcessingDate AND
C.AccountID = p.AccountID AND
C.ProductSymbol = P.ProductSymbol AND
C.DividendValueCur = P.CurrencyCode
INNER JOIN [LiquidCDW].[Transformation].[Mapping_Product_ABNReactor] AS S
ON C.ProductSymbol = S.ReactorProduct AND
S.ValidTo IS NULL AND
S.ProductType = 'E' AND
C.DividendValueCur = S.Currency
WHERE
C.ExdividendDate >= '20210201'
)
SELECT *
FROM cte
WHERE rn = 1
ORDER BY ProductSymbol, CurrencyCode;