Thank you, that makes sense. I've now done it writing the query in SQL one point at a time!
Code:
SELECT Behaviour.[Incident Date], Behaviour.[Pupil Name], Behaviour.[Year group], Behaviour.Role, Behaviour.[Abuse Type], Behaviour.Issue, Behaviour.Consequence, Behaviour.[Staff Involved], Behaviour.OutcomeFROM BehaviourWHERE (Behaviour.[Incident Date] Between Forms![frm_Analysis Builder]!StartDate and Forms![frm_Analysis Builder]!EndDate+1)And (Behaviour.[Year group]=Forms![frm_Analysis Builder]!YearGroup Or IsNull(Forms![frm_Analysis Builder]!YearGroup)) and (Behaviour.[Role]=Forms![frm_Analysis Builder]!Role Or IsNull(Forms![frm_Analysis Builder]!Role)) and (Behaviour.[Abuse Type]=Forms![frm_Analysis Builder]!Type Or IsNull(Forms![frm_Analysis Builder]!Type)) and (Behaviour.[Outcome]=Forms![frm_Analysis Builder]!Outcome Or IsNull(Forms![frm_Analysis Builder]!Outcome));