Option Explicit
      Dim Cn As ADODB.Connection
      Dim Rs As ADODB.Recordset
      Dim strConn As String
      Dim strSQL As String
      Dim FileLength As Long  'Used in Command1 and Command2 procedures.
      Dim Numblocks As Integer
      Dim LeftOver As Long
      Dim i As Integer
      Const BlockSize = 10000 'This size can be experimented with for performance and reliability.

      Private Sub Form_Load()
         Command1.Caption = "AppendChunk"
         Command2.Caption = "GetChunk"
         Command3.Caption = "Exit"
         Command2.Enabled = False

         'Make Connection.
         'Set Cursor type.
         strConn = "UID=MyUID;PWD=MyPassword;" & _
                 "driver={Microsoft ODBC for Oracle};" & _
                 "SERVER=MyServer;"
         Set Cn = New ADODB.Connection
         Cn.CursorLocation = adUseClient
         Cn.Open strConn
         Debug.Print Cn.ConnectionString

      End Sub

      Public Sub Command1_Click()
         ' AppendChunk button.
         ' This procedure prompts for a .txt file,
         ' converts that file to a String Variable,
         ' and saves the String Variable to the table
         ' using the Appendchunk method.
         '
         Dim TextFile As String
         Dim strData As String   'String for LongVarChar data.
         Dim SourceFile As Integer

         ' Open the LARGTEXT table.
         strSQL = "Select MyID, BigText from LARGTEXT WHERE MyID = 1"
         Set Rs = New ADODB.Recordset
         Rs.CursorType = adOpenStatic
         Rs.LockType = adLockOptimistic
         Rs.Open strSQL, Cn

         'Retrieve the text file and update the record.
         CommonDialog1.Filter = "(*.txt)|*.txt"
         CommonDialog1.ShowOpen
         TextFile = CommonDialog1.filename
         Me.MousePointer = vbHourglass
         Me.Caption = "Retrieving the Text File"

         ' Save text file to the table column.
         SourceFile = FreeFile
         Open TextFile For Binary Access Read As SourceFile

         FileLength = LOF(SourceFile)  ' Get the length of the file.
         Debug.Print "Filelength is " & FileLength

         If FileLength = 0 Then

             Close SourceFile
             MsgBox TextFile & " empty or not found."
             Exit Sub
         Else

             Numblocks = FileLength / BlockSize
             LeftOver = FileLength Mod BlockSize

                 Rs(1).AppendChunk Null
                 strData = String(LeftOver, " ")
                 Get SourceFile, 1, strData
                 Rs(1).AppendChunk strData

                 strData = String(BlockSize, " ")

                 For i = 1 To Numblocks
                   Get SourceFile, , strData
                   Rs(1).AppendChunk strData
                 Next i

                 Close SourceFile

             Rs.Update   'Commit the new data.

             Close SourceFile
         End If

         Me.Caption = "Text File Retrieved"
         Command2.Enabled = True
         Me.MousePointer = vbNormal
      End Sub

      Private Sub Command2_Click()
         ' GetChunk Button.
         ' This procedure retrieves the text file
         ' from the table using the GetChunk method,
         ' converts the data to a file and
         ' displays that file in the RichTextBox.
         '
         Dim strData As String   'String for LongVarChar data
         Dim DestFileNum As Integer
         Dim DiskFile As String
         Dim txtOutFile As String
         Dim FileSize As Long

         Me.MousePointer = vbHourglass
         Me.Caption = "Getting the Text File"

         ' Remove any existing destination file.
         DiskFile = App.Path & "\BigText.txt"
         If Len(Dir$(DiskFile)) & 0 Then
            Kill DiskFile
         End If

         DestFileNum = FreeFile
         Open DiskFile For Binary As DestFileNum

         Numblocks = FileLength / BlockSize
         LeftOver = FileLength Mod BlockSize
         FileSize = Rs(1).ActualSize
         Debug.Print "The file size is " & FileSize

         strData = String(FileSize, 32)

         For i = 1 To Numblocks
             strData = String(BlockSize, 32)
             strData = Rs(1).GetChunk(BlockSize)
             Put DestFileNum, , strData
         Next i
         strData = String(LeftOver, 32)
         strData = Rs(1).GetChunk(LeftOver)

         Put DestFileNum, , strData
         Close DestFileNum

         RichTextBox1.LoadFile DiskFile, rtfText

         Rs.Close
         Debug.Print "Complete"
         Me.Caption = "Success!"
         Me.MousePointer = vbNormal

      End Sub

      Private Sub Command3_Click()
          'Exit button.
          Cn.Close
          Unload Me
     End Sub