Dynamic order direction - sql

Question

I writing a SP that accepts as parameters column to sort and direction.
I don't want to use dynamic SQL.
The problem is with setting the direction parameter.
This is the partial code:
SET #OrderByColumn = 'AddedDate'
SET #OrderDirection = 1;
…
ORDER BY
CASE WHEN #OrderByColumn = 'AddedDate' THEN CONVERT(varchar(50), AddedDate)
WHEN #OrderByColumn = 'Visible' THEN CONVERT(varchar(2), Visible)
WHEN #OrderByColumn = 'AddedBy' THEN AddedBy
WHEN #OrderByColumn = 'Title' THEN Title
END

Answer 1

You could have two near-identical ORDER BY items, one ASC and one DESC, and extend your CASE statement to make one or other of them always equal a single value:
ORDER BY
CASE WHEN #OrderDirection = 0 THEN 1
ELSE
CASE WHEN #OrderByColumn = 'AddedDate' THEN CONVERT(varchar(50), AddedDate)
WHEN #OrderByColumn = 'Visible' THEN CONVERT(varchar(2), Visible)
WHEN #OrderByColumn = 'AddedBy' THEN AddedBy
WHEN #OrderByColumn = 'Title' THEN Title
END
END ASC,
CASE WHEN #OrderDirection = 1 THEN 1
ELSE
CASE WHEN #OrderByColumn = 'AddedDate' THEN CONVERT(varchar(50), AddedDate)
WHEN #OrderByColumn = 'Visible' THEN CONVERT(varchar(2), Visible)
WHEN #OrderByColumn = 'AddedBy' THEN AddedBy
WHEN #OrderByColumn = 'Title' THEN Title
END
END DESC

Answer 2

You can simplify the CASE by using ROW_NUMBER which sorts your data and effectively converts it into a handy integer format. Especially since the question is tagged SQL Server 2005
This also expands easily enough to deal with secondary and tertiary sorts
I've used multiplier to again simplify the actual select statement and reduce the chance of RBAR evaluation in the ORDER BY
DECLARE #multiplier int;
SELECT #multiplier = CASE #Direction WHEN 1 THEN -1 ELSE 1 END;
SELECT
Columns you actually want
FROM
(
SELECT
Columns you actually want,
ROW_NUMBER() OVER (ORDER BY AddedDate) AS AddedDateSort,
ROW_NUMBER() OVER (ORDER BY Visible) AS VisibleSort,
ROW_NUMBER() OVER (ORDER BY AddedBy) AS AddedBySort,
ROW_NUMBER() OVER (ORDER BY Title) AS TitleSort
FROM
myTable
WHERE
MyFilters...
) foo
ORDER BY
CASE #OrderByColumn
WHEN 'AddedDate' THEN AddedDateSort
WHEN 'Visible' THEN VisibleSort
WHEN 'AddedBy' THEN AddedBySort
WHEN 'Title' THEN TitleSort
END * #multiplier;

Answer 3

This works fine for me – (where, order by, direction, Pagination)
parameters
#orderColumn int ,
#orderDir varchar(20),
#start int ,
#limit int
select * from items
order by
CASE WHEN #orderColumn = 0 AND #orderdir = 'desc' THEN items.[CategoryName] END DESC,
CASE WHEN #orderColumn = 0 AND #orderdir = 'asc' THEN items.[CategoryName] END ASC,
CASE WHEN #orderColumn = 1 AND #orderdir = 'desc' THEN items.[CategoryValue] END DESC,
CASE WHEN #orderColumn = 1 AND #orderdir = 'asc' THEN items.[CategoryValue] END ASC,
CASE WHEN #orderColumn = 2 AND #orderdir = 'desc' THEN items.[CreatedOn] END DESC,
CASE WHEN #orderColumn = 2 AND #orderdir = 'asc' THEN items.[CreatedOn] END ASC
OFFSET #start ROWS FETCH NEXT #limit ROWS ONLY

Answer 4

Here is an example:
CREATE PROCEDURE GetProducts
(
#OrderBy VARCHAR(50),
#Input2 VARCHAR(30)
)
AS
BEGIN
SET NOCOUNT ON
SELECT Id, ProductName, Description, Price, Quantity
FROM Products
WHERE ProductName LIKE #Input2
ORDER BY
CASE
WHEN #OrderBy = 'ProductNameAsc' THEN ProductName
END ASC,
CASE
WHEN #OrderBy = 'ProductNameDesc' THEN ProductName
END DESC
END
From here:
http://www.dominicpettifer.co.uk/Blog/21/dynamic-conditional-order-by-clause-in-sql-server-t-sql
Ascending and Descending actions need
to be grouped into separate CASE
statements, separated with a comma. In
your server-side code/script make sure
to append 'Asc' or 'Desc' onto the
order by string, or you could have two
Stored procedure input parameters for
column name and order by direction if
you want.

Answer 5

More compact version of accepted answer, but as accepted answer this works fine only when result expressions after THEN have the same type.
ORDER BY
CASE #OrderDirection WHEN 0 THEN
CASE #sortColumn
WHEN 'AddedDate' THEN CONVERT(varchar(50), AddedDate)
WHEN 'Visible' THEN CONVERT(varchar(2), Visible)
WHEN 'AddedBy' THEN AddedBy
WHEN 'Title' THEN Title
END
END ASC,
CASE #OrderDirection WHEN 1 THEN
CASE #sortColumn
WHEN 'AddedDate' THEN CONVERT(varchar(50), AddedDate)
WHEN 'Visible' THEN CONVERT(varchar(2), Visible)
WHEN 'AddedBy' THEN AddedBy
WHEN 'Title' THEN Title
END
END DESC

Answer 6

Dynamic sorting in either ASC or DESC order, irrespective of datatype.
The first example sorts alphabetically, the second using numbers. The #direction variable denotes sort direction (0 = ASC or 1 = DESC) and [column] is the sort column.
This also works for multi-column sorting and you can hide the [row] column if placed in a further outer query.
DECLARE #direction BIT = 1 -- 0 = ASC or 1 = DESC
-- Text sort.
SELECT
IIF(#direction = 0, ROW_NUMBER() OVER (ORDER BY [column] ASC), ROW_NUMBER() OVER (ORDER BY [column] DESC)) [row]
, *
FROM
( -- your dataset.
SELECT N'B' [column]
UNION SELECT N'C'
UNION SELECT N'A'
) [data] ORDER BY [row]
-- Numeric sort.
SELECT
IIF(#direction = 0, ROW_NUMBER() OVER (ORDER BY [column] ASC), ROW_NUMBER() OVER (ORDER BY [column] DESC)) [row],
*
FROM
( -- your dataset.
SELECT 2 [column]
UNION SELECT 3
UNION SELECT 1
) [data] ORDER BY [row]