SQL Server First Value Function

-- SQL Server First Value Function

-- THE FOLLOWING IS A FIRST VALUE FUNCTION USING OVER AND ORDER BY INCLUDING GROUP BY

-- THEORY:

/* SELECT COL1 ,FIRST_VALUE(COL2) OVER (ORDER BY COL1) AS FIRSTVALUE
FROM dATABASEnAME.DBO.TABLENAME AS ALIAS
GROUP BY COL2 , COL1, COL3; */

-- EXAMPLE:

SELECT ACC.AccountType ,FIRST_VALUE(ACC.AccountDescription) OVER (ORDER BY ACC.AccounTTYPE) AS FIRSTVALUE
FROM AdventureWorksDW2012.dbo.DimAccount AS ACC
GROUP BY ACC.AccountDescription ,ACC.AccountType, ACC.AccountKey;

-- EXECUTE (FN F5)