Setting Max ID criteria in Ms Access SQL - sql

Question

This query does not run at the beginning. Could someone please help look at what is wrong?
If there is any other way to achieve this kindly suggest.
strSQL1 = "SELECT * FROM PharmSales WHERE HospitalNo='" & Me.txtRegNo &
"' And TDate = #" & Format(Me.txtTDate, "M\/dd\/yyyy") &
"# AND SalesItem1 = '" & Me.txtSalesItem1 & "' And
PharmSalesID=
(SELECT MAX(PharmSalesID) FROM PharmSales)"
Set pr = db.OpenRecordset(strSQL1)
With pr
If Not .BOF And Not .EOF Then 'Ensure that the recordset contains records
.MoveLast
.MoveFirst
If .Updatable Then 'To ensure record is not locked by another user
.Edit 'Must start an update with the edit statement
If IsNull(![TotalPaid]) = True And Me.txtGrand_TotalPay.Value >= Me.txtSalesAmt1.Value Then
![DispQty1] = Nz(![DispQty1] + Me.txtSalesQty1.Value, 0)
.Update
ElseIf IsNull(![TotalPaid]) = False And (Me.txtGrand_TotalPay.Value - Me.txtSalesAmt1.Value) >= (txtGrand_TotalFee - Me.txtGrand_TotalPay.Value + Me.txtSalesAmt1.Value) Then
![DispQty1] = Nz(![DispQty1] + Me.txtSalesQty1.Value, 0)
.Update
Else: MsgBox ("Insufficient balance!")
End If
End If
End If
pr.Close
Set pr = Nothing
Set db = Nothing
End With
End Sub

Answer 1

Your SQL checks multiple criteria, but your subquery doesn't have any of these criteria, so it will probably select a record that doesn't conform to your other criteria, causing your recordset to always be empty.
You need to add these criteria to the subquery, not the main query.
Since the subquery will just return one record, you don't have to add them to both.
strSQL1 = "SELECT * FROM PharmSales" & _
" WHERE PharmSalesID=" & _
" (SELECT MAX(PharmSalesID) FROM PharmSales" & _
" WHERE HospitalNo='" & Me.txtRegNo & _
"' And TDate = #" & Format(Me.txtTDate, "M\/dd\/yyyy") & _
"# AND SalesItem1 = '" & Me.txtSalesItem1 & "')"