Two Date Criteria in DMin Function in VBA Access - vba

Question

I have a table with Multiple Date Fields like
DOB (Date),
DOA_ASST(Date),
DOA_UDC (Date)
and also have some fields like
ID (AutoNumber),
EmpID (Integer),
EmpName (Text),
SeniorityNumber (Integer) etc.
Many of Employee Promoted Same Date and Also Have the same date of Appointment. I want to provide serial no as per their seniority according to their first date of Appointment.
Criteria are following-
if Multiple Employee Promoted on the Same date then Date of Appointment with older date will be considered, if Date of Appointment are same then Date of Birth with Older date will be considered.
I tried the following code:-
Private Sub cmdProcess_Click()
Dim rst As Recordset
Dim rst1 As Recordset
Dim LastSN As Integer
Dim str, strAsst, strUDC, strLDC As String
Dim LDCDate, UDCDate, AsstDate, BirthDate As Date
AsstDate = Nz(DMax("[DOP_ASST]", "tblDraftSeniority"), DMin("[DOP_ASST]", "tblRawSeniority"))
UDCDate = DMin("[DOP_UDC]", "tblRawSeniority", "[DOP_ASST] = #" & AsstDate & "#")
LDCDate = DMin("[DOA_ESIC]", "tblRawSeniority", "[DOP_UDC] = #" & UDCDate & "# AND [DOP_ASST] = #" & AsstDate & "#")
BirthDate = DMin("[DOB]", "tblRawSeniority", "[DOA_ESIC] = #" & LDCDate & "#")
LastSN = DLookup("[ID]", "tblRawSeniority", "[DOB] = #" & BirthDate & "#")
Set rst = CurrentDb.OpenRecordset("tblRawSeniority")
Set rst1 = CurrentDb.OpenRecordset("tblDraftSeniority")
rst.MoveLast
rst.MoveFirst
Do While rst.EOF = False
If rst!ID = LastSN Then
With rst
Me.txtEmpName1 = rst!EmpName
Me.txtEmpCatg1 = rst!Category
Me.txtEmpDOB1 = rst!DOB
Me.txtEmpDOEntry1 = rst!DOA_ESIC
Me.txtEmpDONextPromo1 = rst!DOP_UDC
Me.txtEmpDOCurrentPromo1 = rst!DOP_ASST
Me.txtEmpStateRegion1 = rst!Region
Me.txtRemark1 = rst!Remark
Me.txtSN1 = rst!SrNoHQRS
End With
End If
rst.MoveNext
Loop
Set rst = Nothing
End Sub
But there is null value in LDCDate with Two date Criteria

Answer 1

Since rst1 is not used, and you are only looking up one ID, you could try something like:
Private Sub cmdProcess_Click()
Dim rst As DAO.Recordset
Dim LastSN As Long
Dim LDCDate As Date
Dim UDCDate As Date
Dim AsstDate As Date
Dim BirthDate As Date
AsstDate = Nz(DMax("[DOP_ASST]", "tblDraftSeniority"), DMin("[DOP_ASST]", "tblRawSeniority"))
UDCDate = Nz(DMin("[DOP_UDC]", "tblRawSeniority", "[DOP_ASST] = #" & Format(AsstDate, "yyyy\/mm\/dd") & "#"), DMax("[DOP_UDC]", "tblRawSeniority"))
LDCDate = Nz(DMin("[DOA_ESIC]", "tblRawSeniority", "[DOP_UDC] = #" & Format(UDCDate, "yyyy\/mm\/dd") & "# AND [DOP_ASST] = #" & Format(AsstDate, "yyyy\/mm\/dd") & "#"), DMax("[DOP_ESIC]", "tblRawSeniority"))
BirthDate = DMin("[DOB]", "tblRawSeniority", "[DOA_ESIC] = #" & Format(LDCDate, "yyyy\/mm\/dd") & "#")
LastSN = Nz(DLookup("[ID]", "tblRawSeniority", "[DOB] = #" & Format(BirthDate, "yyyy\/mm\/dd") & "#"), Date)
Set rst = CurrentDb.OpenRecordset("tblRawSeniority")
rst.FindFirst "ID = " & LastSN & ""
If Not rst.NoMatch Then
Me.txtEmpName1 = rst!EmpName
Me.txtEmpCatg1 = rst!Category
Me.txtEmpDOB1 = rst!DOB
Me.txtEmpDOEntry1 = rst!DOA_ESIC
Me.txtEmpDONextPromo1 = rst!DOP_UDC
Me.txtEmpDOCurrentPromo1 = rst!DOP_ASST
Me.txtEmpStateRegion1 = rst!Region
Me.txtRemark1 = rst!Remark
Me.txtSN1 = rst!SrNoHQRS
End If
rst.Close
Set rst = Nothing
End Sub

Answer 2

Since you are allowing null values for AsstDate, you are most likely using a null value (or 0) in the criteria for the LDCDate DMin lookup. If your table doesn't actually have nulls in the DOP_ASST field, then your LDCDate will be null because there is no result found.