I am having problems with a where statement. I need to have the query bring back results if any of these cases are true. but it only seems to be bringing back instances of where the first statement is true.

where ((t.enrolleddate is null and t.withdrawldate is null)or(t.enrolleddate <= t.classdate and t.withdrawldate is null) or (t.enrolleddate is null and t.withdrawldate >=t.classdate) or (t.enrolleddate <=t.classdate and t.withdrawldate >=t.classdate))

If i run each individual where clause it works ... but when i combine them it does not. can someone please help me