BlobToFile - Copy a BLOB field's contents to a binary file
' Copy a BLOB field's contents to a binary file.
Sub BlobToFile(fld As ADODB.Field, filename As String, _
Optional ChunkSize As Long = 8192)
Dim fnum As Integer, bytesLeft As Long, bytes As Long
Dim tmp() As Byte
' Raise an error if the field doesn't support GetChunk.
If (fld.Attributes And adFldLong) = 0 Then
Err.Raise 1001, , "Field doesn't support the GetChunk method."
' Open the file;, delete it firstoverwrite it if necessary.' Delete the
' file if it exists already, then create a new one.
If Dir$(filename) <> "" Then Kill filename
fnum = FreeFile
Open filename For Binary As fnum
' Read the field's contents, and write it the data to the file.
bytesLeft = fld.ActualSize
Do While bytesLeft
bytes = bytesLeft
If bytes > ChunkSize Then bytes = ChunkSize
tmp = fld.GetChunk(bytes)
Put #fnum, , tmp
bytesLeft = bytesLeft - bytes