Question

Hoping this is trivial for a SQL-Ninja… Been trying to get the following query working:

This is for SQL Server 2008

SELECT 
    ROW_NUMBER() OVER (ORDER BY Date_Time DESC) AS RowNumber, *
FROM
    (SELECT 
         T.A_ID, T.User_Name, T.Date_Time, T.Value,
         U.ID, U.Name, U.Field1, U.Field2,
         COUNT(U.ID) OVER () AS TotalRows
     FROM 
        TeeTable as T 
    INNER JOIN 
        YouTable AS U ON T.U_ID = U.ID
    WHERE 
        T.Value BETWEEN 222 AND 225) Filtered
WHERE 
    RowNumber BETWEEN 1 AND 5

The values are somewhat contrived to give a specific example, but the spirit of the query is completely preserved. The error I get from this statement is:

Invalid column name ‘RowNumber’.

If I remove the final WHERE clause (RowNumber BETWEEN …) it returns an expected result set (A_ID, User_Name, Date_Time etc…), with RowNumber as a column (with sensical values) in said results. Yet I cannot compare against it in the WHERE clause. I’m clearly doing something stupid but this hits my SQL limit!

I’ve tried re-arranging this as a CTE as well, (WITH Filtered AS …) but the end result is the same, it appears that’s just a sugar for what I’m already doing anyway.

Ideas? How can I filter against the RowNumber derived column?

Answer 1

You must move the WHERE operator above the project list where RowNumber column is created. Use a derived table or a CTE:

SELECT * 
  FROM (
   SELECT *, ROW_NUMBER() OVER (...) as RowNumber
   FROM ...) As ...
 WHERE RowNumber = ...

the equivalent CTE is:

WITH cte AS (
SELECT *, ROW_NUMBER() OVER (...) as RowNumber
       FROM ...)
SELECT * FROM cte 
WHERE RowNumber = ...