具有WHERE子句逻辑的SQL Server存储过程

Question

I have a table of results in my application and a box that allows a user to filter the result set by one or more values.

I had to add an optional needBy date to the records so that a person could specify if they need the request to be handled by a certain date.

The part I am struggling with is the filtering of the optional date structure. My filters are as follows:

• Current = All requests that have a need by date less than or equal to today
• Future = All requests with a need by date that is greater than today
• All = All requests both with and without a need by date

Here is an example of my query. The WHERE for everything expect the @needBy is working just fine.

SELECT 
    * 
FROM 
    TABLE
WHERE 
    (@requestor IS NULL OR r.Requestor = @requestor) 
    AND
    (@user IS NULL OR t.QID = @user)
    AND
    (@tool IS NULL OR t.ToolID = @tool)
    AND
    (@role IS NULL OR t.RoleID = @role)
    AND
    (@action IS NULL OR t.ActionID = @action)
    AND
    (@status IS NULL OR t.StatusID = @status)
    AND
    (@needBy IS NULL OR CASE 
                            WHEN @needBy = 'current' THEN r.NeedByDate <= GETUTCDATE()
                            WHEN @needBy = 'future' THEN r.NeedByDate > GETUTCDATE()
                            WHEN @needBy = 'all' THEN r.NeedByDate IS NOT NULL
                        END)

How should I approach this query differently for the dates? The one additional problem is @needBy = 'all' . In this situation, I need all records, regardless of it having a date in the future, in the past, or provided at all.

In my code above, it seems to not like the logic operators that are inside of the WHEN/THEN statement.

Answer 1

You started good with the OR conditions, you just need to go all the way:

SELECT 
    * 
FROM 
    TABLE
WHERE 
    (@requestor IS NULL OR r.Requestor = @requestor) 
    AND
    (@user IS NULL OR t.QID = @user)
    AND
    (@tool IS NULL OR t.ToolID = @tool)
    AND
    (@role IS NULL OR t.RoleID = @role)
    AND
    (@action IS NULL OR t.ActionID = @action)
    AND
    (@status IS NULL OR t.StatusID = @status)
    AND
    (@needBy IS NULL OR 
         (@needBy = 'current' AND r.NeedByDate <= GETUTCDATE()) OR 
         (@needBy = 'future'  AND r.NeedByDate > GETUTCDATE()) OR 
         (@needBy = 'all' AND r.NeedByDate IS NOT NULL)
     )

Please note that catch-all queries often suffer from inefficient execution plan, since it's compiled based on a set of parameters that might not be the best for the next set of parameters.
One solution for that would be to add OPTION(RECOMPILE) to the stored procedure. For more information, Please refer to this blog post

Answer 2

You don't need CASE :

 (@needBy IS NULL OR 
   ( @needBy = 'current' AND r.NeedByDate <= GETUTCDATE() )
   OR 
   ( @needBy = 'future' AND r.NeedByDate > GETUTCDATE() )
   OR 
   ( @needBy = 'all' AND r.NeedByDate IS NOT NULL )
                       )