把存储在SQL7的image字段的文件下载到客户端的ASP源代码

文 件 名：download.asp
使用方法：download.asp?fid=xxx
说　　明：把SQL7的image字段存储的文件下载到客户端
数据库结构：[表名]tabimage　{fid int not null;filename varchar(100) not null;filecontent image not null}
fid:文件id [PK]；filename:文件名；filecontent:文件二进制内容

<%
Response.Buffer=True
varfileid = Request("fid")
If varfileid="" Then
Response.write "没有指定下载文件ID。"
Response.End
End If

OpenDB conn
SQL = "SELECT filename,filecontent FROM tabimage WHERE fid=" & varfileid
Set rs = conn.Execute(SQL)
If Not rs.Eof Then
varfilename = rs("filename")
varfilesize=rs("filecontent").ActualSize
varcontent = rs("filecontent").GetChunk(varfilesize)
Response.ContentType = "*/*"
Response.AddHeader "Content-Length",varfilesize
Response.AddHeader "Content-Disposition", "attachment;filename=""" & varfilename & """"
Response.binarywrite varcontent
End If
rs.Close
Set rs = Nothing
conn.Close
Set conn = Nothing
Response.End

'连接数据库通用过程
Sub OpenDB (ByRef conn)
Set conn = Server.CreateObject("ADODB.Connection")
conn.provider="sqloledb"
conn.ConnectionString = "driver={SQL Server};server=xxx.xxx.xxx.xxx;uid=myusername;pwd=mypassword;database=mydatabase"
conn.Open
End Sub
%>