Stored procedure doesn't allow null parameters even the parameter represent accept nulls?

Question

I saw many questions on stack overflow, non of them touched my own problem

procedure or function expects parameter which was not supplied

Answer 1

You need to check your input for null and use DBNull.Value when you creating the parameters. If you pass just null as a parameter - ADO.Net will ignore that.

EDIT:

You can add that check into your custom method DataAccessLayer.CreateParameter()