how to order 2 SQL Fields in asc and desc dynamically

Question

I want to Order a SQL Select Query where there\'s 2 fields that are in the order by. I then need to decide if one is Descending and the other as Ascending. How is this done<

Answer 1

SELECT 
  Customer_ID,                        
  Name,                               
  Age                                         
FROM
  #Customer
ORDER BY 
  CASE WHEN @field = 'Name' AND @direction = 'A' THEN Name ELSE NULL END ASC,
  CASE WHEN @field = 'Name' AND @direction = 'D' THEN Name ELSE NULL END DESC,
  CASE WHEN @field = 'Age'  AND @direction = 'A' THEN Age  ELSE NULL END ASC,
  CASE WHEN @field = 'Age'  AND @direction = 'D' THEN Age  ELSE NULL END DESC

I wouldn't want to do that over many different combinations though. If you have a lot of combinations I'd do somethign based on the following...

SELECT 
  Customer_ID,                        
  Name,                               
  Age                                         
FROM
(
  SELECT
    Customer_ID,
    Name,
    ROW_NUMBER() OVER (ORDER BY Name) AS "name_order",
    Age,
    ROW_NUMBER() OVER (ORDER BY Age)  AS "age_order"
  FROM
    #Customer
)
  AS [data]
ORDER BY 
  CASE @field1
    WHEN 'Name' THEN CASE @direction1 WHEN 'A' THEN name_order ELSE -name_order END
    WHEN 'Age'  THEN CASE @direction1 WHEN 'A' THEN age_order  ELSE -age_order  END
    ELSE NULL
  END,
  CASE @field2
    WHEN 'Name' THEN CASE @direction2 WHEN 'A' THEN name_order ELSE -name_order END
    WHEN 'Age'  THEN CASE @direction2 WHEN 'A' THEN age_order  ELSE -age_order  END
    ELSE NULL
  END

Repeat as many times as is required...

Note: Just because it can be done this way, doesn't mean it should be done this way.