How do you do a data import/merge using Lotuscript?

This function can be placed in an action button in a database:

Sub Initialize
 On Error Goto _Error

 Dim bFileOpen As Integer
 Dim session As New NotesSession
 Dim db As NotesDatabase
 Set db = session.CurrentDatabase

 Dim view As NotesView
 Dim doc As NotesDocument
 Set view = db.GetView( "(CleanAddress)" )
 Set doc = view.GetFirstDocument

  ' The Fields we are going to import
 Dim Field1 As String
 Dim Field2 As String

  ' The unique field for each record
 Dim UniqueID As String

  ' Name of file to get from user
 Dim FileName As String

 If Not (doc Is Nothing) Then
   FileName  = Inputbox$("Enter your import file name: ", "Data Import", "C:\")
   If (FileName = "") Then
     Messagebox ("Import has been cancelled")
     Exit Sub
   End If
 Else
    ' There is nothing to merge into
   Messagebox ("Nothing to merge into! Are you sure you have already imported this file?")
   Exit Sub
 End If

  ' Open the file
 Dim fileNum As Integer
 fileNum = Freefile()
 Open FileName For Input As fileNum
 bFileOpen = 1

 Dim item As NotesItem
  ' Until we eof
 Do Until Eof (fileNum)
   Input #fileNum, UniqueID, Field1, Field2
   If (UniqueID > "") Then
     Set doc = view.GetDocumentByKey(URN)
     If Not (doc Is Nothing) Then
       doc.Field1 = Field1
       doc.Field2 = Field2
       Call doc.Save(True, False)
     Else
       Messagebox("File contains a record that is not in the database " + UniqueID)
     End If
   Else
     Messagebox("File contains an record without a unique id")
   End If
 Loop

  ' Close file
 Close fileNum
 bFileOpen = 0

 Messagebox("File imported successfully")
 Exit Sub

_Error:
 If (bFileOpen = 1) Then
   Close fileNum
 End If
 Messagebox("Error importing data: " + Error$)
End Sub

Applies to Notes Versions: 4, 4.5, 4.6, 5