I have query that is build from user's inputs ( passed via html form). It looks like (simple example):
Select * From [table] Where [table].[column] like '<parameter>'
This parameter may be optional so if user left corresponding input field empty I pass %. It worked fine until I encountered NULL values. I understand that '%' match symbols not null, but i would like to consider NULL as empty string in this case.
What should I do? Change query (how?) or pass another symbol(s) when user left empty input?
Thanks.
PS. It's real problem from existing system and i know it's far from optimal solution, but i have to deal with it.