SQL dynamic ORDER BY using alias

Question

Using SQL Server, I can order a normal SELECT query using an alias:

SELECT   
   u.FirstName + \' \' + u.LastName as PhysicianName, COUNT(r.Id)          


        

Answer 1

Column aliases defined in the SELECT can only be used in the ORDER BY on their own. Not in an expression.

You can adjust your original attempt as follows.

;WITH T
     AS (SELECT u.FirstName + ' ' + u.LastName AS PhysicianName,
                COUNT(r.Id)                    AS ReferralsCount
         FROM   Referrals r
                INNER JOIN Users u
                  ON r.PhysicianId = u.Id
         GROUP  BY r.PhysicianId,
                   u.FirstName,
                   u.LastName)
SELECT *
FROM   T
ORDER  BY CASE
            WHEN @orderby = 'PhysicianName' THEN PhysicianName
          END,
          CASE
            WHEN @orderby = 'ReferralsCount' THEN ReferralsCount
          END