Question

I feel like this deserves a good comment but I get the feeling that what I have is merely a distraction.

1. Does this deserve a comment?
2. If so, can this comment be improved?

Please note that I am working with a poorly normalized application.

(   
    /* Remove Time Portion From ActivityDate */  
    DateAdd(Day, DateDiff(Day, 0, Activity.ActivityDate), 0) Not Between        
    /* Remove Time Portion From @MinimumDate Or SQL Server Min DateTime */   
    DateAdd(Day, DateDiff(Day, 0, Coalesce(@MinimumDate, '1753-01-01')), 0) And
    /* Remove Time Portion From @MaximumDate Or SQL Server Max DateTime */  
    DateAdd(Day, DateDiff(Day, 0, Coalesce(@MaximumDate, '9999-12-31')), 0) 
)

Answer 1

I’d wrap the dateadd/datediff in a scalar udf with a self commenting name and then pass in Activity.ActivityDate or Coalesce(@MinimumDate, '1753-01-01')) as parameters

So you’d have this:

(   
    dbo.ufnGetDateOnly (Activity.ActivityDate) NOT BETWEEN        
         dbo.ufnGetDateOnly (COALESCE(@MinimumDate, '1753-01-01')) AND
         dbo.ufnGetDateOnly (COALESCE(@MaximumDate, '9999-12-31')) 
)

You could also have a “date if null” parameter and deal with COALESCE in the udf if it’s common enough in the SQL code

(   
    dbo.ufnGetDateOnly (Activity.ActivityDate, DEFAULT) NOT BETWEEN        
         dbo.ufnGetDateOnly (@MinimumDate, '1753-01-01') AND
         dbo.ufnGetDateOnly (@MaximumDate, '9999-12-31') 
)

Now it’s obvious…no?