First_Value Function return first value in an ordered set of values in SQL Server 2012.This function must have an OVER clause.
Syntax:
FIRST_VALUE(Column_Name) Over (Order By Column_Name ASC)
Example:
Create table #Temp ( ID int identity(1,1) , EmployeeName varchar(100), Age int ) Insert into #Temp(EmployeeName,Age) Select 'Hitesh',25 union Select 'Priyanka',23 union Select 'Dev',33 union Select 'Neha',25 union Select 'Abhimanyu',22 union Select 'Bhawesh',30
SQL Query using FIRST_VALUE Function
Select ID, EmployeeName, Age, FIRST_VALUE(Age) OVER (ORDER BY EmployeeName ASC) from #Temp
Result:
This Result will return 22.