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I am new on here, and had a newbie question that I am stumped with.
I am not new to access, but am new to VB.
I am trying to export BLOBs from a field called photo to external jpeg files. I have tried the MS kb 210486 and successfully got the import/export to work with a sample table, but only the first record. I do not wish to impost binary data to the database, it's already there. I simply wish to pick up the binary BLOB from the photo field and export it to an image file, autonaming it.
Here is a sample of my table.
IDnumber | Lastname | Firstname | Address | Photo |
----------------------------------------------------------------------------
12485881 | Simpson | Homer...... |12 Hills St| long binary data |
12335682 | Fernando | Manny.......| 1 Elm St | long binary data |...
I am trying to take all the BLOBs under the "photo" field and export them to jpgs using the IDnumber field as the filename.
I have cut the code down to the following as I do not need to import an image in, it is already there. After cutting it down this far, I am getting an ambiguous name: Copyfile.
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- Option Explicit
- Const BlockSize = 32768
- '**************************************************************
- ' FUNCTION: WriteBLOB()
- '
- ' PURPOSE:
- ' Writes BLOB information stored in the specified table and field
- ' to the specified disk file.
- '
- ' PREREQUISITES:
- ' The specified table with the OLE object field containing the
- ' binary data must be opened in Visual Basic code and the correct
- ' record navigated to prior to calling the WriteBLOB() function.
- '
- ' ARGUMENTS:
- ' T - The table object containing the binary information.
- ' sField - The OLE object field in table T containing the
- ' binary information to write.
- ' Destination - The path and filename to write the binary
- ' information to.
- '
- ' RETURN:
- ' The number of bytes written to the destination file.
- '**************************************************************
- Function WriteBLOB(T As DAO.Recordset, sField As String, _
- Destination As String)
- Dim NumBlocks As Integer, DestFile As Integer, i As Integer
- Dim FileLength As Long, LeftOver As Long
- Dim FileData As String
- Dim RetVal As Variant
- On Error GoTo Err_WriteBLOB
- ' Get the size of the field.
- FileLength = T(sField).FieldSize()
- If FileLength = 0 Then
- WriteBLOB = 0
- Exit Function
- End If
- ' Calculate number of blocks to write and leftover bytes.
- NumBlocks = FileLength \ BlockSize
- LeftOver = FileLength Mod BlockSize
- ' Remove any existing destination file.
- DestFile = FreeFile
- Open Destination For Output As DestFile
- Close DestFile
- ' Open the destination file.
- Open Destination For Binary As DestFile
- ' SysCmd is used to manipulate the status bar meter.
- RetVal = SysCmd(acSysCmdInitMeter, _
- "Writing BLOB", FileLength / 1000)
- ' Write the leftover data to the output file.
- FileData = T(sField).GetChunk(0, LeftOver)
- Put DestFile, , FileData
- ' Update the status bar meter.
- RetVal = SysCmd(acSysCmdUpdateMeter, LeftOver / 1000)
- ' Write the remaining blocks of data to the output file.
- For i = 1 To NumBlocks
- ' Reads a chunk and writes it to output file.
- FileData = T(sField).GetChunk((i - 1) * BlockSize _
- + LeftOver, BlockSize)
- Put DestFile, , FileData
- RetVal = SysCmd(acSysCmdUpdateMeter, _
- ((i - 1) * BlockSize + LeftOver) / 1000)
- Next i
- ' Terminates function
- RetVal = SysCmd(acSysCmdRemoveMeter)
- Close DestFile
- WriteBLOB = FileLength
- Exit Function
- Err_WriteBLOB:
- WriteBLOB = -Err
- Exit Function
- End Function
- '**************************************************************
- ' SUB: CopyFile
- '
- ' PURPOSE:
- ' Demonstrates how to use ReadBLOB() and WriteBLOB().
- '
- ' PREREQUISITES:
- ' A table called BLOB that contains an OLE Object field called
- ' Blob.
- '
- ' ARGUMENTS:
- ' Source - The path and filename of the information to copy.
- ' Destination - The path and filename of the file to write
- ' the binary information to.
- '
- ' EXAMPLE:
- ' CopyFile "c:\windows\winfile.hlp", "c:\windows\winfil_1.hlp"
- '**************************************************************
- Sub CopyFile(Destination As String)
- Dim BytesWritten As Variant
- Dim Msg As String
- Dim db As DAO.Database
- Dim T As DAO.Recordset
- ' Open the University table.
- Set db = CurrentDb()
- Set T = db.OpenRecordset("University", dbOpenTable)
- ' Create a new record and move to it.
- T.AddNew
- T.Update
- T.MoveLast
- BytesWritten = WriteBLOB(T, "Photo", Destination)
- Msg = "Finished writing """ & Destination & """"
- Msg = Msg & Chr$(13) & ".. " & BytesWritten & " bytes written."
- MsgBox Msg, 64, "Copy File"
- End Sub
