Oracle中带有CASE语句的条件WHERE子句

I'm brand-new to the Oracle world so this could be a softball. In working with an SSRS report, I'm passing in a string of states to a view. The twist is that the users could also pick a selection from the state list called "[ No Selection ]" ... (that part was not by doing and I'm stuck with implementing things this way) I'm brand-new to the Oracle world so this could