DCount Type Mismatch Error VBA - excel

Question

I'm trying to use DCount to see if records exist in a table before inserting the data into the database but I keep getting a type mismatch error on "Customer Number" and have no idea why. The code is below:
Public Sub ExportData()
Set cn = CreateObject("ADODB.Connection")
dbPath = Application.ActiveWorkbook.Path & "\PRID.mdb"
dbWb = Application.ActiveWorkbook.FullName
dbWs = Application.ActiveSheet.Name
scn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & dbPath
dsh = "[" & Application.ActiveSheet.Name & "$]"
cn.Open scn
ssql = "INSERT INTO [Investment Data] ([Customer Number])"
ssql = ssql & "SELECT [Customer Number] FROM [Excel 8.0;HDR=YES;DATABASE=" & dbWb & "]." & dsh
If Application.WorksheetFunction.DCount("Customer Number", "Investment Data", "[Customer Number]=" & Range("A2")) > 0 Then
MsgBox ("A similar entry has been detected within the PRID database, please make sure that this is a new entry before you continue.")
Else
MsgBox ("Entry has been entered into the database.")
cn.Execute ssql
Exit Sub
End If
Any help would be appreciated thanks.

Answer 1

This should resolve your problem
You can add a WHERE clause to your query that will skip the [Customer Number] that already exists in the [Investment Data] table.
ssql = ssql & _
" WHERE [Customer Number] NOT IN(SELECT [Customer Number] FROM [Investment Data]);)"
You can then use Connection.Execute to return the number of records added.
Results = cN.Execute(ssql)
MsgBox Results & " Records were added " & (allRecordsCount - Results) & "Records Were Skipped"
If you want to alert the user before you insert the records you'll need two queries.
ssql = ssql & "SELECT [Customer Number] FROM [Excel 8.0;HDR=YES;DATABASE=" & dbWb & "]." & dsh & _
ssql & " WHERE [Customer Number] IN(SELECT [Customer Number] FROM [Investment Data]);)"
Set rs = CreateObject("ADODB.Recordset")
Set rs = cN.Execute(ssql)
If Not rs.BOF AND Not rs.EOF Then
msg = msg & vbCrLf & rs.Fields("Customer Number").Value
rs.MoveNext
End If
If msg <> "" Then
MsgBox "These Records Are Duplicates" & vbCrLf & msg
Exit Sub
End If
This should answer your question
You are getting the "DCount Type Mismatch Error VBA" because you are trying to query an external Access Database using the Excel WorksheetFunction DCount.
Test Queries
Public Sub TestQueries()
Set cN = CreateObject("ADODB.Connection")
Set rs = CreateObject("ADODB.Recordset")
dbPath = Application.ActiveWorkbook.path & "\PRID.mdb"
'dbPath = "C:\Users\best buy\Downloads\stackoverfow\Sample Data File\test.mdb"
dbWb = Application.ActiveWorkbook.FullName
dbWs = Application.ActiveSheet.Name
scn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & dbPath
dsh = "[" & Application.ActiveSheet.Name & "$]"
cN.Open scn
ssql = ssql & "SELECT [Customer Number] FROM [Excel 8.0;HDR=YES;DATABASE=" & dbWb & "]." & dsh
Set rs = cN.Execute(ssql)
Do While Not rs.BOF And Not rs.EOF
msg = msg & vbCrLf & rs.FIelds(0).Value
rs.MoveNext
Loop
MsgBox msg, vbInformation, "Results Query Without Where Clause"
ssql = ssql & _
" WHERE [Customer Number] IN(SELECT CDbl([Customer Number]) FROM [Investment Data])"
msg = ""
Set rs = cN.Execute(ssql)
Do While Not rs.BOF And Not rs.EOF
msg = msg & vbCrLf & rs.FIelds(0).Value
rs.MoveNext
Loop
MsgBox msg, vbInformation, "Results Query With Where Clause"
End Sub