T-SQL Conditional Order By

Question

I am trying to write a stored procedure that returns a list of object with the sort order and sort direction selected by the user and passed in as sql parameters.

Le

Answer 1

I stumbled on this when I was trying to do a similar thing, however the select statement I was creating includes a rather large and ugly string concatenation which severely limited my ability to use a dynamic SQL approach. If you have simple search cases, this is a decent solution.

That being said, another way to do this in SQL server specifically is with a table variable. This requires more overhead and complexity but it also gives you a lot of flexibility.

DECLARE @RawProducts TABLE (
    product_id int, 
    name varchar(50), 
    value int, 
    created_date datetime
)
INSERT INTO @RawProducts
SELECT * FROM [Product]

IF @sortOrder = 'name' AND @sortDir = 'asc' BEGIN
    SELECT * FROM @RawProducts
    ORDER BY [name] ASC
END

IF @sortOrder = 'name' AND @sortDir = 'desc' BEGIN
    SELECT * FROM @RawProducts
    ORDER BY [name] desc
END

IF @sortOrder = 'created_date' AND @sortDir = 'asc' BEGIN
    SELECT * FROM @RawProducts
    ORDER BY [created_date] ASC
END

IF @sortOrder = 'created_date' AND @sortDir = 'desc' BEGIN
    SELECT * FROM @RawProducts
    ORDER BY [created_date] desc
END

One drawback to this methodology is that you will need to add a case block for each and every case you want to order by but you would have to do that with any solution that does not involve dynamic SQL.

The only time I would recommend this method is if you have a relatively small data set and you have easy to discern search cases.