SQL Server ORDER BY [aggregation] DESC/ASC

Question

I want to be able to sort [comment] by ascending or descending. I've tried performing the aggregation again in the "order by" clause, but that didn't work. I also tried sorting outside of the sub query which let me use the alias [comment], but that only sorted between rows 0 and 10.

This query is a smaller version of a much larger query.

SELECT *
FROM   (SELECT ISNULL((SELECT COUNT("order")
                       FROM   order_comment
                       WHERE  "order" = "order"."id"
                       GROUP  BY "order"), 0)                 AS [comment],
               Row_number() OVER (ORDER BY "order"."id" DESC) AS [rownum]
        FROM   [order]
        WHERE  ISNULL((SELECT COUNT("order")
                       FROM   order_comment
                       WHERE  "order" = "order"."id"
                       GROUP  BY "order"), 0) > 0) AS [filter]
WHERE  [rownum] BETWEEN 0 AND 10

So easy in MySql!

SELECT Ifnull((SELECT COUNT(`order`)
               FROM   order_comment
               WHERE  `order` = `order`.`id`
               GROUP  BY `order`), 0) AS `comment`
FROM   `order`
HAVING `comment` > 0
ORDER  BY `comment` DESC
LIMIT  0, 10  

Answer 1

Following latest edit suspect you want something like this

;WITH oc AS
(
SELECT [order], 
       COUNT([order]) AS order_count
FROM   order_comment 
GROUP  BY [order]
), occ AS
(
SELECT o.*,
       order_count AS comment,
       ROW_NUMBER() OVER (ORDER BY order_count DESC) AS  [rownum]
FROM [order] o
INNER JOIN oc ON oc.[order] = o.id
)
SELECT *
FROM occ 
WHERE  [rownum] BETWEEN 0 AND 10
ORDER BY [rownum]

The INNER JOIN will already exclude any rows with no child rows in order_comment

Answer 2

I assume that you don't know that you can use the OVER clause with aggregate functions.

COUNT(order) OVER(PARTITION BY id) AS [comment]
....
ORDER BY [comment]

Answer 3

in SQL Server you can order by column number from your query as in ORDER BY 1 more info here http://blog.sqlauthority.com/2010/12/27/sql-server-order-by-columnname-vs-order-by-columnnumber/

SELECT *
FROM   (SELECT ISNULL((SELECT COUNT("order")
                      FROM   order_comment
                   WHERE  "order" = "order"."id"
                   GROUP  BY "order"), 0)                 AS [comment],
           Row_number() OVER (ORDER BY "order"."id" DESC) AS [rownum]
    FROM   [order]
    WHERE  ISNULL((SELECT COUNT("order")
                   FROM   order_comment
                   WHERE  "order" = "order"."id"
                   GROUP  BY "order"), 0) > 0) AS [filter]
WHERE  [rownum] BETWEEN 0 AND 10
 ORDER BY 1