Using a SQL Ranking Function with a derived column

Question

I am trying to use a SQL Server 2008 Ranking Function on a query sorted by a derived column. Here's an example

SELECT 
    table.FirstName, table.LastName, 
    CalculatedValue(table.number) As Points, 
    ROW_NUMBER() OVER (ORDER BY points) AS 'Row Number' 
FROM table 
ORDER BY points

I always get an error invalid column name "points" because the OVER function does not work with aliases, based on what I've read.

Does anyone know an alternative where I can retrieve the sequential row number of a result set sorted by a derived column?

Answer 1

How about using a derived table (sub query)? I think something like the following should work

SELECT 
    ROW_NUMBER() OVER (ORDER BY sub.Points) AS 'Row Number',
    sub.FirstName,
    sub.LastName,
    sub.Points
FROM
(

    SELECT 
        table.FirstName, 
        table.LastName, 
        CalculatedValue(table.number) As Points
    FROM 
        table    
) sub
ORDER BY
    sub.Points

Answer 2

Use a CTE to calculate your Points, then rank over the CTE.

 WITH tableWithPoints AS (
   SELECT 
       table.FirstName, table.LastName, 
       CalculatedValue(table.number) As Points
   FROM table)

 SELECT FirstName, LastName, Points,
     ROW_NUMBER() OVER (ORDER BY Points) AS 'Row Number' 
 FROM 
     tableWithPoints ORDER BY Points