how to compare value enter with null value in database

Question

Hi all I am developing web App using C#. and sqlserver 2005 My problem isAssume user enter his data in to databasethen it compare the datetime of Now with datetime present in database.(i have a column Createdon(datetime)).and it restrict the user to enter same data in same date. but problem is Assume if user entering his data for first time how its will check with database time?

Manish Dwivedi · Answer

Hi if user entering his data for first time then check the existence of the user data on the table on that day.