Conditional SQL ORDER BY ASC/DESC for alpha columns

Question

Writing a stored procedure in MS SQL Server 2008 R2, I want to avoid using DSQL...

I would like the sort method (ASC or DESC) to be conditional.

Now, with a

Answer 1

This is one of those cases when specific solutions may be preferable preferable to generic ones, especially when we deal with large amounts of data. I would:

IF @OrderAscOrDesc = 0 THEN BEGIN
  SELECT ...
  FROM  ... 
  ORDER BY [AlphaColumn] ASC
END ELSE BEGIN
  SELECT ...
  FROM  ... 
  ORDER BY [AlphaColumn] DESC
END

If you have an index on [AlphaColumn], you might sometimes get a better plan with a more specific query, than with a generic one-size-fits-all one.

Edit: to facilitate code reuse, you can wrap your select in an inline UDF - it will perform just as well:

IF @OrderAscOrDesc = 0 THEN BEGIN
  SELECT ...
  FROM  YourInlineUdf(...)
  ORDER BY [AlphaColumn] ASC
END ELSE BEGIN
  SELECT ...
  FROM  YourInlineUdf(...) 
  ORDER BY [AlphaColumn] DESC
END