Scheduling Conflict: can only detect conflict with exact time - visual-studio

Question

This is the last problem I have to face in for my capstone project, and it's driving me nuts.
Basically, I have to be able to identify if Section/Faculty/Room are all in use when scheduling a subject, to avoid conflicts.
Here's what I've worked on, but so far it can only detect when Room is in use.
I can't figure out how to be able to prevent scheduling that's in-between time periods. For example: First entry would be 7-8:30AM. Second entry would be 7:30 AM to 9 AM. With the former existing, it should reject the latter but I can't figure out how to do that. This is what I've cooked up so far. How would you guys go about this?
Public Function DataInUse() As Boolean
Dim Temp As Boolean
Temp = False
If FacultyInUse() = True Then
MessageBox.Show("Faculty in use.")
cboFaculty.Focus()
DisplayFacultyInUse()
DisplayLabelConflictForFaculty()
Temp = True
ElseIf RoomInUse() = True Then
MessageBox.Show("Room in use.")
cboRoom.Focus()
DisplayRoomInUse()
DisplayLabelConflictForRoom()
Temp = True
End If
Return Temp
End Function
Public Function FacultyInUse() As Boolean
Dim com As New OleDbCommand(" Select * from qrySubjectOfferring Where cTimeIn >=#" & cboFrom.Text & "# and cTimeOut <=#" & cboTo.Text & "# and Faculty like'" & cboFaculty.Text & "%' and cDay Like '%" & cboDay.Text & "%'", clsCon.con)
Dim dr As OleDbDataReader = com.ExecuteReader()
dr.Read()
If dr.HasRows Then
Return True
Else
Return False
End If
End Function
Public Function RoomInUse() As Boolean
Dim com As New OleDbCommand("Select * from qryRoomAvailability WHERE (cTimeIn <=#" & cboFrom.Text & "# AND cTimeOut >=#" & cboFrom.Text & "# AND Room = '" & cboRoom.Text & "' AND cDay = '" & cboDay.Text & "') OR (cTimeIn <=#" & cboTo.Text & "# AND cTimeOut >=#" & cboTo.Text & "# AND Room = '" & cboRoom.Text & "' AND cDay = '" & cboDay.Text & "') OR (cTimeIn >= #" & cboFrom.Text & "# AND cTimeOut <= #" & cboTo.Text & "# AND Room = '" & cboRoom.Text & "' AND cDay = '" & cboDay.Text & "') ", clsCon.con)
Dim dr As OleDbDataReader = com.ExecuteReader()
dr.Read()
If dr.HasRows Then
Return True
Else
Return False
End If
End Function
Public Function SubjectAlreadyOffered(sSubject As String) As Boolean
Dim com As New OleDbCommand("Select * from qrySubjectOfferring Where Subject LIKE '%" & sSubject & "%'", clsCon.con)
Dim dr As OleDbDataReader = com.ExecuteReader()
dr.Read()
If dr.HasRows Then
Return True
Else
Return False
End If
End Function

Answer 1

Try simplifying your SQL to use Between clause and eliminate all entries where the From or To are in existing entries
In your RoomInUse() function
Dim strSQL as String
strSQL = "SELECT * FROM qryRoomAvailability WHERE " & _
" Room = '" & cboRoom.Text & "' AND cDay = '" & cboDay.Text & "'" & _
" AND NOT (#" & cboFrom.Text "# BETWEEN [" & cTimeIn & "] AND [" & cTimeOut & "])" & _
" AND NOT (#" & cboTo.Text "# BETWEEN [" & cTimeIn & "] AND [" & cTimeOut & "])"
Dim com As New OleDbCommand(strSQL, clsCon.con)