Preventing duplicate row entries

Hello,

I am looking into creating a macro that would be prevent the entry of duplicate rows of data, within a worksheet. If the input text exists, there should be a warning message, with no option to leave the duplicated item.

I found the below coding in a different thread. Would it be possible to adjust the below coding to identify duplicate rows of data, from columns A to I? Please let me know if you require more information.

Thanks,
Ken

Code:

Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Range)

If Target.Cells.Count > 1 Then Exit Sub

Dim mySum As Integer

mySum = 0

If Sh.Name = "Sheet1" Or Sh.Name = "Sheet2" Then ' the names of sheets where col A checked
    If Target.Column <> 1 Then Exit Sub
    mySum = mySum + Application.CountIf(Sh.Range("A:A"), Target.Value)
    If mySum > 1 Then
        MsgBox "Invoice Already Exists"
        With Application
            .EnableEvents = False
            .Undo
            .EnableEvents = True
        End With
    End If
ElseIf Sh.Name = "Sheet3" Then                 ' the name of sheet where col E checked
    If Target.Column <> 5 Then Exit Sub
    mySum = mySum + Application.CountIf(Sh.Range("E:E"), Target.Value)
    If mySum > 1 Then
        MsgBox "Invoice Already Exists"
        With Application
            .EnableEvents = False
            .Undo
            .EnableEvents = True
        End With
    End If
End If

End Sub