Question

I have a select which needs to have dynamic WHERE CASE conditions.

SELECT 
      *
FROM 
      vwShowUctyPohyby
WHERE
      (@id_parent is null or id_parent=@id_parent)
      and (datetime_creation <= @record_first_datetime)
ORDER BY 
      CASE @sort_order WHEN 0 THEN datetime_creation END ASC, 
      CASE @sort_order WHEN 1 THEN datetime_creation END DESC  

As you can see there is a condition to dynamically choose type of ORDER. Now I need to do same with WHERE part. I found that it can work like datetime_creation = CASE ….. WHEN … THEN …. END.

Problem is that I need to create datetime_creation <= @record_first_datetime for one WHERE condition and datetime_creation >= @record_first_datetime for other condition.

How do I do that? I dont want to create two selects and use IF ELSE statement.

I am using this SELECT for dynamic paging on SQL side, with ROWCOUNT.

Answer 1

Is this your intention ?

SELECT  * 
FROM  vwShowUctyPohyby 
WHERE 
      (@id_parent is null or id_parent=@id_parent) 
      and 
      ((datetime_creation <= @record_first_datetime and @sort_order = 0) or
      (datetime_creation >= @record_first_datetime and @sort_order = 1))
ORDER BY  
      CASE @sort_order WHEN 0 THEN datetime_creation END ASC,  
      CASE @sort_order WHEN 1 THEN datetime_creation END DESC