I can tell at a glance what `where` and `having` mean - the former is a filter over a result set, and the latter is a filter over a grouping.

You're probably right that SQL should have earlier defined this sort of recursion, so that you could sequence groupings and filters more easily, but don't fret: that future is here with common table expressions. Recursion is even supported!

I'm reminded of this abomination of a query I wrote in 2010 that produced a numbers table:

http://blogs.msdn.com/b/sqlazure/archive/2010/09/16/10063301...

Code:

    DECLARE @N int = 1000000;

      WITH RecursiveRowGenerator (Row#, Iteration) AS (
           SELECT 1, 1
            UNION ALL
           SELECT Row# + Iteration, Iteration * 2
             FROM RecursiveRowGenerator
            WHERE Iteration * 2 < CEILING(SQRT(@N))
            UNION ALL
           SELECT Row# + (Iteration * 2), Iteration * 2
             FROM RecursiveRowGenerator
            WHERE Iteration * 2 < CEILING(SQRT(@N))
         )
         , SqrtNRows AS (
           SELECT *
             FROM RecursiveRowGenerator
            UNION ALL
           SELECT 0, 0
         )
    SELECT TOP(@N) 1 + A.Row# * POWER(2,CEILING(LOG(SQRT(@N))/LOG(2))) + B.Row# Row#
      FROM SqrtNRows A, SqrtNRows B
     ORDER BY A.Row#, B.Row#;