Question

in the following sql query i have a select case without else

 SET dateformat mdy 
    DECLARE @DATE1 DATETIME 
    SET @DATE1 = '12/31/2011' 
    DECLARE @DATE2 DATETIME 
    SET @DATE2 = '06/01/2012' 


    UPDATE tablx
    SET xdate = case WHEN xdate is null and odate BETWEEN @Date1 AND @Date2 then odate end

does the existance of else make difference, in the above case would the xdate value be filled with NULL if the condition is not met even if i didnt write ELSE NULL?

Answer 1

It doesn’t make any semantic difference ELSE NULL is the default if omitted.

Perhaps including the redundant ELSE explicitly might be clearer for potential readers unaware of this fact though.