I'm getting ready to use SQL Server 2008's FileStream capability but I'm not sure if Classic ASP can read and write from SQL 2008 FileStream. We still have an old application we'd like to update to support File Uploads to data开发者_JAVA技巧base and would like to consider FileStream. If needed I can build a COM object via .NET to handle this but would like to know if there is a better way, thanks!
Here is some example code. I have not tried it, but got it from http://www.experts-exchange.com/Microsoft/Development/MS_Access/Access_Coding-Macros/Q_24772719.html:
Function Download_File(SQL_Txt As String, Conn As ADODB.Connection, FieldName As String, Fname As String, Optional FPath As String = "") As String
Dim Z As Variant, I As Long, Fn As String, Max As Long, X As New ADODB.Recordset, Fx As New FileSystemObject
Dim FieldType As ADODB.DataTypeEnum
Const Delta = 32768
On Error GoTo Download_File_Err
I = 1
Download_File = ""
X.CursorLocation = adUseServer
X.Open SQL_Txt, Conn, adOpenStatic, adLockReadOnly
Max = X(FieldName).ActualSize
FieldType = X(FieldName).Type
If FieldType = adLongVarChar Then
Z = X(FieldName).GetChunk(Delta) 'Legggi la porzione di file...
Else
'FieldType =adLongVarBinary ->sicuramente!
Z = BinaryToString(X(FieldName).GetChunk(Delta))
End If
'Apri-Crea il nuovo file e scrivi la prima porzione di file...
Fx.OpenTextFile(Fn, ForWriting, True).Write Z
While Len(Z) > 0
If FieldType = adLongVarChar Then
Z = Nz(X(FieldName).GetChunk(Delta), "")
Else
Z = BinaryToString(X(FieldName).GetChunk(Delta))
End If
'Salva la porzione di file...
Fx.OpenTextFile(Fn, ForAppending, False).Write Z
I = I + 1
Wend
X.Close
Set Fx = Nothing
Msg
Download_File = Fn 'Segnala avvenuto scaricamento del file con nome e percorso...
Exit Function
Download_File_Err:
MsgBox Err.Description
Msg
X.Close
Set Fx = Nothing
End Function
Public Function Upload_File(SQL_Txt, Conn As ADODB.Connection, FieldName As String, Optional FPath_and_Name As String = "") As String
Dim Z As String, L As Long, Fx As New FileSystemObject, X As New ADODB.Recordset
Dim FieldType As ADODB.DataTypeEnum
Const Delta = 16384
On Error GoTo Upload_File_err
Upload_File = ""
L = FileLen(FPath_and_Name)
'In questo caso si usa il cursore lato server... (Ma perchè il cursore lato client fallisce?)
X.CursorLocation = adUseServer
X.Open SQL_Txt, Conn, adOpenDynamic, adLockOptimistic
FieldType = X(FieldName).Type
If FieldType = adLongVarChar Then
'Leggi tutti i caratteri dal file...
Z = Fx.OpenTextFile(FPath_and_Name, ForReading).Read(L)
X.Update FieldName, Z
Else
Z = Fx.OpenTextFile(FPath_and_Name, ForReading).Read(L)
X.Update FieldName, StringToBinary(Z)
End If
X.Close
Msg
Upload_File = FPath_and_Name
Exit Function
Upload_File_err:
MsgBox Err.Description
X.Close
Msg
End Function
Function BinaryToString(ByteArray As Variant) As String
'--- Fast Converts the binary content to text
'Antonin Foller, http://www.motobit.com
Dim X As New ADODB.Recordset, L As Long
BinaryToString = ""
If IsNull(ByteArray) Then Exit Function
L = LenB(ByteArray)
If L > 0 Then
X.Fields.Append "mBinary", adLongVarChar, L
X.Open
X.AddNew
'In questo caso particolare AppendChunk converte l'array di byte
'in stringa! fantastico.
X("mBinary").AppendChunk ByteArray
X.Update
BinaryToString = X("mBinary")
End If
X.Close
End Function
Function StringToBinary(S As String) As Variant
'Converts the string into a Binary array()
'Standard conversion...
Dim I As Long, V As Variant
StringToBinary = Null
If S = "" Then Exit Function
ReDim V(0 To Len(S) - 1) As Byte
For I = 1 To Len(S)
V(I - 1) = Asc(Mid(S, I, 1))
Next I
StringToBinary = V
End Function
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